Best Practice & Research Clinical Obstetrics and Gynaecology 28 (2014) 495–506
Contents lists available at ScienceDirect
Best Practice & Research Clinical Obstetrics and Gynaecology journal homepage: www.elsevier.com/locate/bpobgyn
3
Congenital heart disease in pregnancy Lorna Swan, MB ChB, FRCP, MD, Consultant Cardiologist * Adult Congenital Heart Disease Unit, Royal Brompton Hospital, London SW3 6NP, UK
Keywords: congenital heart disease pregnancy pre-conception counselling
The story of congenital heart disease is one of the major successes of medicine in the last 50 years. Heart conditions previously associated with early death are now successfully treated. Many of these women are now in their child-bearing years wishing to have children of their own. All of these women should be offered comprehensive pre-conception counselling by a dedicated multidisciplinary team. Each woman will present a unique set of cardiac and obstetric challenges that require an individualised assessment of risk and a carefully documented care plan. In this chapter, I describe the most common forms of congenital heart disease and the specific issues that should be assessed before conception. I present a systematic approach to risk stratification and care planning. These lesions range from mild disease with little implications for pregnancy to those with a sizable risk of maternal mortality or complications. I will also discuss fetal risk factors. Ó 2014 Elsevier Ltd. All rights reserved.
Introduction With the successful repair and palliation of many forms of congenital heart disease in childhood, a growing population of people are now surviving into adulthood with even complex cardiac lesions [1]. These people have a desire to live as ‘normal’ lives as possible, and having children is part of their expectations for the future. Congenital heart disease is a rare cause of maternal cardiac mortality; however, a large proportion of women attending pre-pregnancy cardiac obstetric clinics have congenital heart disease [2]. The fact that these women have known cardiac disease enables comprehensive pre-conception counselling and
* Tel.: þ44 (0) 207349 7748; Fax: þ44 (0) 207351 8518. E-mail address: [email protected]. http://dx.doi.org/10.1016/j.bpobgyn.2014.03.002 1521-6934/Ó 2014 Elsevier Ltd. All rights reserved.
496
L. Swan / Best Practice & Research Clinical Obstetrics and Gynaecology 28 (2014) 495–506
optimisation of care to take place [3]. In contrast, many women with acquired heart disease often present for the first time during pregnancy. Unsurprisingly, most maternal cardiac fatalities occur within this group [4]. It is difficult to establish precisely the extent of maternal morbidity associated with congenital heart disease. In one of the largest studies on cardiac maternal morbidity [5], congenital heart disease was not labelled as a separate category. The small number of participants with congenital heart disease were listed under those with valve disease. It has been hypothesised that improved pre-conception counselling and antenatal care have led to an improvement in maternal outcomes in congenital heart disease compared with other forms of maternal cardiac disease [6]. A wide spectrum of congenital heart lesions exists, ranging from the benign lesion with no effect on longevity to life-shortening conditions that may be highly symptomatic. Some women may present with a cardiac lesion that has a unique anatomy and physiology, and therefore preconception advice and management plans must be tailored to the individual patient. It is understandable that the evidence base for practice is rather patchy in this heterogenous population, and many of the treatment recommendations are based on clinical consensus [7]. It is, therefore, essential that these women are cared for by a team of experienced clinicians in a multi-disciplinary environment [8].
Principles of pre-conception counselling Preconception counselling should be offered to all women with congenital heart disease who are of child-bearing age. This advice must be given by a specialist multi-disciplinary team with both cardiac and obstetric input. The advice given should be tailored to the unique anatomy and physiology of each particular women. The key components of comprehensive counselling are presented in Table 1. Several simple scoring systems have been developed to assist clinicians in their attempts to effectively risk stratify women contemplating pregnancy. The most commonly used of these are the Cardiac Disease in Pregnancy (CARPREG) score and the ZAHARA (Zwangerschap bij Aangeboren
Table 1 World Health Organization risk groups for people with congenital heart lesions.a WHO risk group I No detectable increased risk of maternal mortality, and no or mild increase in morbidity. Uncomplicated mild lesions. small patent duct or mild pulmonary stenosis. Successfully repaired simple lesions. WHO risk group II (if uncomplicated). Small increased risk of maternal mortality or moderate increase in morbidity. Unrepaired atrial septal or ventricular septal defect. Repaired Tetralogy. WHO risk group II-III (depends on individual patient). Lesions with mild ventricular dysfunction. Native or tissue valve disease (most). Repaired coarctation. WHO risk group III Significantly increased risk of maternal mortality or severe morbidity. Mechanical valves. Systemic right ventricle. Fontan circulation. People with cyanosis and other complex lesions. WHO risk group IV Extremely high risk of maternal mortality or severe morbidity; pregnancy contraindicated. Pulmonary hypertension. Severe systemic ventricular dysfunction. Severe left heart obstruction (including coarctation). a
Adapted from Thorne et al. [30]; WHO, World Health Organization.
L. Swan / Best Practice & Research Clinical Obstetrics and Gynaecology 28 (2014) 495–506
497
Table 2 Pre-pregnancy counselling check list. Maternal risks What are the CARPREG, ZAHARA and modified WHO scores? What is current functional class? Cardiac symptoms? Is there a risk of arrhythmia? Are there any pacing or device issues? Is there a risk of ventricular dysfunction? Is cyanosis an issue? Thrombotic and bleeding risks? Is the pulmonary artery pressure normal? Are there obstructive lesions? Is there a risk of coronary ischaemia? Is there a risk of dissection or aortic rupture? Is there an increased risk of hypertension? Are there drugs that need to be changed or discontinued? Are there other lifestyle issues? Is the patient a smoker? Are there any specific obstetric risks? Are there any fertility issues? Issues about long-term prognosis? Fetal risks Risk due to maternal low cardiac output? Risk due to maternal cyanosis? Risk due to maternal medication? Risks due to maternal lifestyle and smoking? Risk of prematurity or growth restriction? Genetic and recurrence risks?
Hartafwijking) score (Table 2) [9,10]. Although far from comprehensive, these scoring systems offer additional tools to approximate risk. An alternative scale that is also informative is the modified World Health Organization pregnancy classification. This has four categories of risk from class I (little additional risk from pregnancy) to class IV (pregnancy is extremely high risk and should be considered contraindicated) [11]. Determinants of fetal outcome in congenital heart disease Most research on congenital heart disease has focused on maternal outcomes in pregnancy. A key determinant of fetal outcome is maintaining maternal health. Some maternal features are a specific risk to the fetus. These include maternal symptoms, cyanosis, anticoagulation, cigarette smoking, multiple gestation and left heart obstruction [9]. In addition, maternal drug treatments may also adversely affect the fetus; the most common of these are oral anticoagulants [12] and beta-blockers [13]. An important component of pre-pregnancy counselling is assessing the potential fetal affects of cardiac drugs. Ideally, women should be taking a minimum number of essential drugs, and, where possible, drugs with safety concerns should have been discontinued or substituted by alternatives. Risk of recurrence of congenital heart defects in offspring Many congenital heart defects have a familial basis. The live birth risk of congenital heart disease is 0.8% for the general population [14]; in mothers with congenital heart disease, this risk is in the region of 3–5% [15]. This average, however, covers a divergent group of conditions. In a few circumstances, an autosomal dominant inheritance pattern exists (with a 50% recurrence risk). This group includes patients with Di George syndrome (22q11 deletion). These women often have conotruncal lesions, including Tetralogy of Fallot and truncus arteriosus. All women with these lesions should be offered genetic testing before pregnancy [16]. Other sub-groups of congenital heart disease have a higher heritability than the average 3–5% value often quoted. These include bicuspid aortic valve disease, atrioventricular septal defect, and atrial septal defect [17]. For all of these conditions, an estimation of recurrence risk should be individualised to the woman’s lesion and their family history. All pregnant
498
L. Swan / Best Practice & Research Clinical Obstetrics and Gynaecology 28 (2014) 495–506
women with a personal or partner history of congenital heart disease should be offered a detailed fetal echocardiogram at 16–23 weeks’ gestation [18]. Defects not detected before pregnancy It is unusual for congenital heart defects to be detected for the first time during pregnancy. A whole range of detects, however, can be been discovered either during routine antenatal review or when the woman presents with an acute complication during pregnancy. A sub-group of these women may have been told they had a heart defect in childhood, but then were either lost to cardiac follow up or never had an opportunity for a full cardiac assessment. Immigrants sometimes fall into this latter category [8]. The most common defects detected in pregnancy include atrial septal defects and mild valve lesions. Women with no previous history of heart disease do not have the opportunity to receive preconception counselling; the most effective way of managing these women is to have pre-defined referral pathway to specialist multi-disciplinary care, which can be triggered as soon as a suspected abnormality is detected. Principles governing delivery Many clinical teams have strong views about the merits and limitations of vaginal delivery compared with caesarean section. These views are not evidence based, but rely on personal experience and anecdote. In congenital heart disease, the mode of delivery is rarely determined by cardiac features alone, and is more frequently an obstetric decision. The gestational age of the fetus will also be an important contributing factor. Vaginal delivery, particularly when accompanied by effective regional anaesthesia, is associated with less haemodynamic change than caesarean section. Thrombosis and bleeding are also less problematic. An elective caesarean section delivery may have logistical advantages. Delivery planning should be a multi-disciplinary (e.g. obstetrician, cardiologist, anaesthetist, neonatologist and patient) decision, and plans should be made and communicated well in advance of the due date. In women with congenital heart disease, it is particularly important that the extended team understand the patient’s anatomy and physiology, and are aware of the normal resting variables, such as oxygen saturations. Care should be taken to identify obstetric drugs that may cause cardiac instability, and limitations should be set regarding the duration of the second stage if contemplating a vaginal delivery. Additional prophylactic antibiotics are not required over and above normal obstetric practice [19]. Specific congenital heart disease lesions In the following section, I discuss several specific forms of congenital heart disease. This is not an exhaustive list and, a wide variety of pathologies exist within each category. For example, a woman with repaired Tetralogy of Fallot may have a near normal heart, but may have a complex lesion with aortopulmonary collateral arteries and cyanosis. As stated previously, each woman will require a unique assessment and management plan. Septal defects One of the most common forms of congenital heart disease is the group of lesions known as septal defects. These include defects of the atrial septum (atrial septal defect [ASD] or patent foramen ovale [PFO]) and of the ventricular septum (ventricular septal defect [VSD]). This group also includes the more complex lesion – the atrioventricular septal defect (AVSD). Most septal defects will be detected in childhood. The exception to this is the isolated atrial septal defect. Women with ASDs may have few clinical signs and remain asymptomatic until presenting for the first time in pregnancy. The principles guiding the management of all of these septal defect lesions are similar, and focus on the haemodynamic significance of the defect.
L. Swan / Best Practice & Research Clinical Obstetrics and Gynaecology 28 (2014) 495–506
499
Defects of the atrial septum Atrial septal defects are associated with a left to right shunt across the atrial septum. The degree of shunting will depend on the size of the defect and the compliance of the right heart. A typical secundum ASD will result in volume loading of the right heart, with dilatation of the right atrium and right ventricle. The function of the right ventricle is usually well preserved but may become impaired over time. Intracardiac shunting results in excessive pulmonary blood flow. With an unoperated atrial septal defect, a full pre-pregnancy or pregnancy assessment will include an assessment of the right ventricular volume loading and function. A dilated right ventricular may be associated with effort intolerance. Poor right ventricular function is unusual, but would be a concern if present. Another key component that needs to be assessed is the pulmonary artery pressure and pulmonary vascular resistance. This will be the major determinant of maternal outcome. In atrial septal defects, the pulmonary artery pressure is often elevated because of increased pulmonary blood flow, but pulmonary vascular resistance is rarely significantly elevated. Each woman should also have their arrhythmia profile assessed. Atrial septal defects are associated with an increased risk of atrial arrhythmias [20], and these may be more troublesome during pregnancy. If these are short or asymptomatic, then they rarely need treatment. Atrial septal defects and PFOs may be associated with a risk of paradoxical embolism in pregnancy [21]. This is compounded by the hypercoagulable state associated with pregnancy. Women with additional risk factors, or those who have had a previous embolic event, may need to be given antiplatelet or anticoagulants during pregnancy and the puerperium. An ASD can be repaired either surgically or using percutaneous devices. The repaired defect is rarely a challenge to pregnancy, although arrhythmia and issues of pulmonary vascular disease still need to be fully assessed. The unrepaired defect rarely needs to be considered for closure during pregnancy, as it is well tolerated and generally women are asymptomatic. A PFO is present in up to 20% of the population. It is of no haemodynamic significance in most cases, although when associated with other cardiac defects such as pulmonary stenosis, it may lead to right to left shunting of blood across the PFO. In a small select group of women, a PFO may be a risk factor for stroke. It is only in this limited setting that a PFO may be important during pregnancy. If the PFO has not been closed, it may be of value to increase the anticoagulant regimen in a woman who has had a previous cryptogenic stroke. Atrioventricular septal defect The atrioventricular septal defect is a more complex lesion associated with abnormalities of the atrioventricular valves and both the atrial and ventricular septum. The simplest of this spectrum of disorders is the isolated primum ASD; the most complex, a complete AVSD, involves atrial and ventricular septal defects and a common atrioventricular valve. In women with either unoperated or operated AVSD, the key components that need to be considered before pregnancy and during pregnancy are the status of the atrioventricular valves because regurgitation is common in ventricular function and the pulmonary artery pressures. An unoperated AVSD may result in Eisenmenger physiology (see below). Ventricular septal defects In contrast to an ASD, a ventricular septal defect is often detected on routine examination, as it is invariably associated with a loud systolic murmur. For this reason, most significant defects are diagnosed and surgically treated in childhood. Device closure is possible but less common. Most unoperated VSDs in adulthood are small and restrictive, with normal pulmonary artery pressure. Paradoxical embolism is rare, as it has a large left to right shunt and pressure gradient. Women with either unoperated VSDs or with late repair may have associated pulmonary vascular disease (see below). Women with an uncomplicated repaired VSD or small restrictive defects should have a normal obstetric course and will require little additional support.
500
L. Swan / Best Practice & Research Clinical Obstetrics and Gynaecology 28 (2014) 495–506
The other common intra-cardiac shunt is the patent ductus arteriosus (PDA). This should be assessed in a manner similar to the VSD with the key issues of left ventricular volume loading and the detection of pulmonary hypertension. In adults, unoperated PDAs are unusual but may be of varying severities from a small insignificant defect to those with Eisenmenger physiology. When assessing a woman with a PDA, it is important to look for ‘differential cyanosis’ – that is near normal saturations in the upper body but cyanosis in the lower limbs. Tetralogy of Fallot Tetralogy of Fallot is one of the most commonly repaired congenital lesions seen in adulthood. Tetralogy is characterized by a large VSD, override of the aorta and obstruction to pulmonary blood flow either at the valve or sub-valvar. Surgical repair includes closing the VSD with a patch and opening up the right ventricular outflow tract and pulmonary valve. Unoperated Tetralogy is rare in adulthood, and is associated with cyanosis and severe right ventricular hypertrophy. In operated individuals, residual lesions are common; these include residual pulmonary valve disease (usually post-surgical pulmonary regurgitation) and residual VSDs. Pulmonary regurgitation is a common finding after repair of Tetralogy, and more than 70% of women will go on to need replacement of their pulmonary valve later in life. Chronic pulmonary regurgitation leads to progressive dilatation of the right ventricle, and eventually impairment of right ventricular function. Women who are contemplating pregnancy should be fully assessed before pregnancy, and may need valve pulmonary replacement before conception. Women who become pregnant with severe pulmonary regurgitation further dilate their right ventricles and may develop effort intolerance or arrhythmia [22,23]. Chronic pulmonary regurgitation is also associated with intrauterine growth restriction [24]. Pulmonary stenosis Isolated pulmonary stenosis (or pulmonary stenosis in the setting of repaired Tetralogy) is usually well tolerated. Over time, however, progressive right ventricular hypertrophy and dilatation of the right atrium (RA) may occur. Again, atrial arrhythmia and effort intolerance may occur. Overt right heart failure is rare. Women with pulmonary stenosis tend to have a good pregnancy outcome. Valvar pulmonary stenosis may be amenable to balloon valvuloplasty but this is rarely required during pregnancy [25]. Many women with more complex congenital heart defects have been repaired using right ventricular to pulmonary artery conduits. These are assessed in the same way as a native pulmonary valve. Echocardiography and cardiac magnetic imaging may both be required to assess conduit function and the right ventricle fully [26]. Left ventricular outflow tract obstruction Aortic valve disease will be discussed in another section. In women contemplating pregnancy, however, most aortic valve disease is congenital in origin. Part of congenital anomaly may include a deficiency in the number of aortic valve cusps (unicuspid or more commonly a bicuspid valve). These valves may be either stenotic, regurgitant, a combination of both, or have normal function. Prepregnancy assessment must include a full assessment of the haemodynamic significance of the valve lesion and the presence or absence of aortic dilatation. In general, aortic regurgitation is well tolerated during pregnancy. Again, the key issue is the size and function of the left ventricle. In women with aortic stenosis, a full assessment will include an echocardiogram, electrocardiogram, exercise tolerance test, and cardiac magnetic resonance scan. Concerning features would include the presence of symptoms, resting or exercise stress test changes on the electrocardiogram, the presence of significant left ventricular hypertrophy (LVH), and left atrium dilatation. A pre-conception exercise test may provide additional prognostic information. A good effort capacity with an appropriate blood pressure and heart rate response would be reassuring. A drop of blood pressure on exercise may highlight a women who might struggle to increase her cardiac output during pregnancy.
L. Swan / Best Practice & Research Clinical Obstetrics and Gynaecology 28 (2014) 495–506
501
In general, an aortic gradient on echo of less than 64 mmHg is usually well tolerated. Over this level, the other features listed above become important. The presence of concerning features or a high aortic valve gradient should trigger a discussion about valve surgery before pregnancy. If a woman with significant aortic stenosis does become pregnant, then an attempt to stratify the risks associated with continuing with the pregnancy should be made. Women with high-risk features may wish to consider termination of pregnancy. If isolated valvar stenosis with minimal regurgitation is diagnosed, then ballooning the valve if the woman shows signs of instability may be an option [27]. Surgical replacement of the aortic valve during pregnancy is possible in extreme circumstances, although cardiopulmonary bypass is associated with a high rate of fetal loss [28]. Women with less extreme compromise are best managed conservatively. Beta-blockers may play some role if a large dynamic component is associated with left ventricular outflow tract obstruction. Diuretics may be needed if symptoms of high left atrial pressure develop (e.g. breathlessness and dry cough). Bed rest and monitoring of fetal growth may be needed in the third trimester in women who become more symptomatic. Early delivery may be necessary in women who are unstable. The principles that guide delivery will be to minimise the haemodynamic effect of the fixed aortic stenotic lesion. The ideal mode of delivery is controversial but vaginal delivery under a low-dose epidural is proposed by many. Drugs that lead to vasodilatation should be avoided, and the second stage should be assisted in women with all but mild stenosis. Coarctation of the aorta Coarctation of the aorta is usually repaired in the neonatal period. Various surgical techniques have been used in the past, including several techniques now known to be associated with late complications. The most concerning of these was the Dacron patch repair, which is often associated with late false aneurysms. Unoperated coarctation can present in pregnancy with severe hypertension. Management of the hypertension may be problematic, as a large gradient may cross the coarctation. Reduction of maternal upper body blood pressure may compromise the fetoplacental unit. Stenting of the coarctation can be carried out during pregnancy if the risk of maternal stroke or heart failure due to uncontrolled hypertension is a concern [29]. In women who have undergone surgery, a key component of maternal outcome will be the detection and timely treatment of hypertension. In women with a subclavian flap repair of coarctation, left arm pulses may be absent, and blood pressure should be taken in the right arm. Hypertension during pregnancy is usually effectively treated with beta-blockers, but other anti-hypertensive agents can be used if needed to maintain normotension, including calcium antagonists and methyldopa. Fetal growth should be monitored in the third trimester. In women with a known coarctation repair site aneurysm, pregnancy would be a risk factor for rupture, and should therefore be delayed until it is treated surgically or treated by percutaneous replacement of a covered stented. If the original type of surgical repair is unknown, then a pre-pregnancy (or pregnancy) cardiac magnetic resonance scan should be carried out. Most women with a coarctation will also have a bicuspid aortic valve, and some will have dilatation of the ascending aorta. Transposition of the great arteries Transposition is a group of conditions that have ‘dis-cordance’ between the ventricles and the great arteries (Fig. 1) [30]. In both subtypes (L-transposition [congenitally corrected transposition] and in simple D-transposition) the right ventricle is connected to the aorta and is the systemic pump. In congenitally corrected transposition, other lesions may be associated (e.g. VSD, pulmonary valve stenosis, or an Ebstein-like abnormality of the tricuspid valve). The crucial determinant of outcome is the function of the systemic right ventricle. The principles that guide the management of these women are the same as for other forms of ventricular dysfunction. Women with severe systemic right ventricular dysfunction should be counselled against pregnancy, as the risk of developing heart failure is high.
502
L. Swan / Best Practice & Research Clinical Obstetrics and Gynaecology 28 (2014) 495–506
Fig. 1. Transposition of the great arteries and its various forms in adulthood. LV, left ventricle; RA, right atrium; RV, right ventricle; RV*, signified lesions with a RV supporting the systemic circulation.
In contrast with congenitally corrected transposition, women with dextro-transposition of the great arteries require life-saving surgery in the first few days of life. Historically, this was an atrial switch (Mustard or Senning) operation. These women have an intra-atrial repair to redirect the venous inflow into the heart. The right ventricle remains in the sub-systemic position, and, again, its function is the main determinant of outcome. Women with atrial switch operations are also prone to arrhythmias, which may be exacerbated by pregnancy. Nowadays, the transposition of the great arteries is repaired by the arterial switch operation, which became the standard surgical repair from the 1980s onwards. In this operation, the two great arteries are ‘switched’. In general, this leaves a heart with few surgical sequelae that pose an issue during pregnancy. The other major surgical technique used was the Rastelli operation, using a right ventricular to pulmonary artery conduit, and a patch repair of the VSD tunnelling the left ventricular to the aorta. For women with a Rastelli, the main focus before pregnancy is function of the right ventricle to pulmonary artery conduit, which over time may become obstructed or regurgitant. Function of the left and right ventricles should also be assessed.
Cyanotic cardiac defects (without pulmonary hypertension) A variety of congenital heart defects are associated with a degree of systemic cyanosis. This can range from cyanosis only evident on exercise to profound resting desaturation and with oxygen saturations 70 mg/l or over. Chronic cyanosis has an effect on many organ systems, all of which may be important during pregnancy. It is associated with an erythrocytosis (isolated high haemoglobin level), low platelets and clotting abnormalities, and haemoglobin may be in excess of 20 g/dL in some women.
L. Swan / Best Practice & Research Clinical Obstetrics and Gynaecology 28 (2014) 495–506
503
Pregnant women may be more prone to bleeding and thrombotic events. Cyanosis also increases the risk of infections, including atypical infections and cerebral abscess. One of the more challenging components of desaturation is its affect on fetal outcome. When resting oxygen saturations fall below 85%, the chance of a live birth is greatly diminished at less than 12% [31]. Early pregnancy loss and intrauterine death both increase in line with decreasing oxygen saturations and increasing maternal haemoglobin levels. Oxygen therapy and bed rest may be used to try to improve fetal growth, but growth restriction and preterm delivery remain common. Eisenmenger physiology Eisenmenger physiology is a form of severe pulmonary hypertension secondary to a long-standing left to right shunt. With time, the pulmonary vascular resistance rises and eventually becomes equal to the systemic pressure. As a consequence, the left to right intra-cardiac shunt decreases and finally reverses leading to cyanosis. In addition to the risks of cyanosis, the woman also has severe pulmonary vascular disease. Eisenmenger syndrome is associated with a high maternal and fetal risk, and women with Eisenmenger syndrome should be advised against pregnancy [32]. Although treatment has improved, maternal mortality remains in excess of 20% [33]. If a woman presents in early pregnancy, then termination should be considered, although the termination itself may be associated with maternal morbidity and even mortality [34]. If a woman with Eisenmenger syndrome chooses to continue with a pregnancy, oxygen therapy, aggressive use of pulmonary vasodilator therapies, and care by a specialist multidisciplinary team, may help to minimise mortality [35]. The major causes of death in this population are right ventricular failure, pulmonary hypertension crisis, arrhyththmia, and stroke. Specialist counselling and contraceptive advice is essential among women with Eisenmenger syndrome. Ebstein anomaly A rarer form of congenital heart disease is the Ebstein anomaly. This is an abnormality of the right heart, with displacement of the tricuspid valve and tricuspid regurgitation. Common associated lesions are a PFO or ASD atrial arrhythmias secondary to accessory condition pathways. People with Ebstein anamoly are frequently cyanosed. The factors predicting maternal and fetal outcome are the presence of severe tricuspid regurgitation, right ventricular function, the degree of cyanosis, and a history of arrhythmia. In the absence of these adverse features, pregnancy is usually well
Fig. 2. Maternal and fetal implications of a Fontan Circulation. IVC, inferior vena cava; LA, left atrial; RA, right atrial; RPA, right pulmonary artery; SVC, superior vena cava.
504
L. Swan / Best Practice & Research Clinical Obstetrics and Gynaecology 28 (2014) 495–506
tolerated with a good outcome [36]. Severe Ebstein anomaly, however, should be repaired before pregnancy. The Fontan operation and other single ventricles The Fontan operation was developed in the 1970s to provide a surgical solution for women whose anatomy was such that biventricular circulation could not be created. In the Fontan operation and its modern iterations, the systemic venous return (the superior and inferior vena cava) is anastomosed directly on to the pulmonary arteries. The effective single ventricle supports the systemic circulation. A proportion of women with single ventricle physiology may never have been considered for a Fontan operation – these were either women with a ‘balanced’ circulation with a large VSD and some form of limitation to pulmonary blood flow (e.g. either pulmonary stenosis or a surgically placed pulmonary artery band) or with unrestricted pulmonary blood flow and secondary pulmonary hypertension. In both of these latter groups, severe cyanosis will be present. Women with a Fontan circulation are at risk of thrombus formation, as venous return is slow flowing. Those with older versions of the Fontan (e.g. the right atrial-to-pulmonary artery connection) will usually be fully anticoagulated; those with more efficient total cavopulmonary connections will be given antiplatelet therapy only. During pregnancy, the anticoagulant regimen will need to be escalated, and many women are treated with low molecular weight heparins. The Fontan circulation presents a unique physiology with important implications for pregnancy and delivery [37]. For effective pulmonary blood flow, the patient must have a sufficient filling pressure. Periods of hypotension or bleeding will be poorly tolerated. Atrial arrhythmias are common in this patient group and, if sustained, they are considered to be a medical emergency and require electrical cardioversion, usually under general anaesthesia with external pacing pads in place. If cardioversion is required in pregnancy, the fetal heart rate should be checked before and after. Fetal bradycardias have been documented [38]. Meticulous fluid balance is required at the time of delivery, and great care should to be taken to avoid anything that may increase pulmonary artery pressure or cause a drop in filling pressures. Again cyanosis is common in women with a Fontan circulation, although saturations are usually above 85%. Intrauterine growth restriction and preterm delivery are common (Fig. 2). Conclusion Increasing numbers of women with repaired and palliated congenital heart disease are now of child-bearing age. Counselling and optimally managing these women during pregnancy requires a team of multi-disciplinary clinicians and established referral pathways.
Practice points An increasing number of women with congenital heart disease are reaching child-bearing age, and all of them should be offered advice regarding contraception, pregnancy, and recurrence risk. Congenital heart disease is fortunately a rare cause of maternal death but it does present management issues for both the mother and the fetus. Pre-conception advice and pregnancy planning needs to be tailored to the individual patient who may have a unique anatomy and physiology. Multi-disciplinary care is particularly important in this area where the evidence base is sparse.
L. Swan / Best Practice & Research Clinical Obstetrics and Gynaecology 28 (2014) 495–506
505
Research agenda Many questions on pregnancy and congenital heart disease remain unanswered. The research opportunities are extensive and have the potential to address clinical questions that will directly affect patient care. These include:
Further investigation of the effect of pregnancy on ventricular function. Research into the effect of pregnancy on long-term maternal cardiac outcomes. Research into the fetal risks of newer anticoagulant drugs. Further study into the familial and genetic determinants of congenital heart disease.
References [1] Opotowsky AR, Siddiqi OK, Webb GD. Trends in hospitalizations for adults with congenital heart disease in the U.S. J Am Coll Cardiol 2009;54:460–7. [2] Valente AM, Landzberg MJ, Gianola A, et al. Improving heart disease knowledge and research participation in adults with congenital heart disease (The Health, Education and Access Research Trial: HEART-ACHD). Int J Cardiol 2013;168:3236– 40. [3] Curry R, Swan L, Steer PJ, et al. Cardiac disease in pregnancy. Curr Opin Obstet Gynecol 2009;21:508–13. *[4] Malhotra S, Yentis SM. Reports on Confidential Enquiries into Maternal Deaths: management strategies based on trends in maternal cardiac deaths over 30 years. Int J Obstet Anesth 2006;15:223–6. *[5] Huisman CM, Zwart JJ, Roos-Hesselink JW, et al. Incidence and predictors of maternal cardiovascular mortality and severe morbidity in The Netherlands: a prospective cohort study. PLoS One 2013;8:e56494. *[6] Cantwell R, Clutton-Brock T, Cooper G, et al. Saving mothers’ lives: reviewing maternal deaths to make motherhood safer: 2006–2008. The Eighth Report of the Confidential Enquiries into Maternal Deaths in the United Kingdom. BJOG 2011; 118(Suppl. 1):1–203. *[7] Regitz-Zagrosek V, Blomstrom Lundqvist C, Borghi C, et al. ESC Guidelines on the management of cardiovascular diseases during pregnancy: the Task Force on the Management of Cardiovascular Diseases during Pregnancy of the European Society of Cardiology (ESC). Eur Heart J 2011;32:3147–97. [8] Gelson E, Gatzoulis MA, Steer P, et al. Heart disease: why is maternal mortality increasing? BJOG 2009;116:609–11. *[9] Siu SC, Sermer M, Colman JM, et al. Prospective multicenter study of pregnancy outcomes in women with heart disease. Circulation 2001;104:515–21. *[10] Drenthen W, Boersma E, Balci A, et al. Predictors of pregnancy complications in women with congenital heart disease. Eur Heart J 2010;31:2124–32. [11] Roos-Hesselink JW, Duvekot JJ, Thorne SA. Pregnancy in high risk cardiac conditions. Heart 2009;95:680–6. [12] Mehndiratta S, Suneja A, Gupta B, et al. Fetotoxicity of warfarin anticoagulation. Arch Gynecol Obstet 2010;282:335–7. [13] Gelson E, Curry R, Gatzoulis MA, et al. Effect of maternal heart disease on fetal growth. Obstet Gynecol 2011;118:364. [14] van der Linde D, Konings EE, Slager MA, et al. Birth prevalence of congenital heart disease worldwide: a systematic review and meta-analysis. J Am Coll Cardiol 2011;58:2241–7. *[15] Burn J, Brennan P, Little J, et al. Recurrence risks in offspring of adults with major heart defects: results from first cohort of British collaborative study. Lancet 1998;351:311–6. [16] Chessa M, Butera G, Bonhoeffer P, et al. Relation of genotype 22q11 deletion to phenotype of pulmonary vessels in tetralogy of Fallot and pulmonary atresia-ventricular septal defect. Heart 1998;79:186–90. [17] Fesslova V, Brankovic J, Lalatta F, et al. Recurrence of congenital heart disease in cases with familial risk screened prenatally by echocardiography. J Pregnancy 2011;2011:368067. *[18] Gill HK, Splitt M, Sharland GK, et al. Patterns of recurrence of congenital heart disease: an analysis of 6,640 consecutive pregnancies evaluated by detailed fetal echocardiography. J Am Coll Cardiol 2003;42:923–9. *[19] Baumgartner H, Bonhoeffer P, De Groot NM, et al. ESC Guidelines for the management of grown-up congenital heart disease (new version 2010). Eur Heart J 2010;31:2915–57. [20] Gatzoulis MA, Freeman MA, Siu SC, et al. Atrial arrhythmia after surgical closure of atrial septal defects in adults. N Engl J Med 1999;340:839–46. [21] Daehnert I, Ewert P, Berger F, et al. Echocardiographically guided closure of a patent foramen ovale during pregnancy after recurrent strokes. J Interv Cardiol 2001;14:191–2. [22] Uebing A, Arvanitis P, Li W, et al. Effect of pregnancy on clinical status and ventricular function in women with heart disease. Int J Cardiol 2010;139:50–9. [23] Balci A, Drenthen W, Mulder BJ, et al. Pregnancy in women with corrected tetralogy of Fallot: occurrence and predictors of adverse events. Am Heart J 2011;161:307–13. [24] Gelson E, Gatzoulis M, Steer PJ, et al. Tetralogy of Fallot: maternal and neonatal outcomes. BJOG 2008;115:398–402. [25] Loya YS, Desai DM, Sharma S. Mitral and pulmonary balloon valvotomy in pregnant patients. Indian Heart J 1993;45:57–9. [26] Babu-Narayan SV, Kilner PJ, Li W, et al. Ventricular fibrosis suggested by cardiovascular magnetic resonance in adults with repaired tetralogy of fallot and its relationship to adverse markers of clinical outcome. Circulation 2006;113:405–13.
506
L. Swan / Best Practice & Research Clinical Obstetrics and Gynaecology 28 (2014) 495–506
[27] Myerson SG, Mitchell AR, Ormerod OJ, et al. What is the role of balloon dilatation for severe aortic stenosis during pregnancy? J Heart Valve Dis 2005;14:147–50. [28] Chandrasekhar S, Cook CR, Collard CD. Cardiac surgery in the parturient. Anesth Analg 2009;108:777–85. [29] Assaidi A, Sbragia P, Fraisse A. Transcatheter therapy for aortic coarctation with severe systemic hypertension during pregnancy. Catheter Cardiovasc Interv 2013;82:556–9. [30] Thorne S, MacGregor A, Nelson-Piercy C. Risks of contraception and pregnancy in heart disease. Heart 2006;92:1520–5. [31] Presbitero P, Somerville J, Stone S, et al. Pregnancy in cyanotic congenital heart disease. Outcome of mother and fetus. Circulation 1994;89:2673–6. [32] Yentis SM, Steer PJ, Plaat F. Eisenmenger’s syndrome in pregnancy: maternal and fetal mortality in the 1990s. Br J Obstet Gynaecol 1998;105:921–2. [33] Bedard E, Dimopoulos K, Gatzoulis MA. Has there been any progress made on pregnancy outcomes among women with pulmonary arterial hypertension? Eur Heart J 2009;30:256–65. [34] Satoh H, Masuda Y, Izuta S, et al. Pregnant patient with primary pulmonary hypertension: general anesthesia and extracorporeal membrane oxygenation support for termination of pregnancy. Anesthesiology 2002;97:1638–40. *[35] Kiely DG, Condliffe R, Webster V, et al. Improved survival in pregnancy and pulmonary hypertension using a multiprofessional approach. BJOG 2010;117:565–74. [36] Katsuragi S, Kamiya C, Yamanaka K, et al. Risk factors for maternal and fetal outcome in pregnancy complicated by Ebstein anomaly. Am J Obstet Gynecol 2013;209:452.e1–6. [37] Drenthen W, Pieper PG, Roos-Hesselink JW, et al. Pregnancy and delivery in women after Fontan palliation. Heart 2006; 92:1290–4. [38] Tromp CH, Nanne AC, Pernet PJ, et al. Electrical cardioversion during pregnancy: safe or not? Neth Heart J 2011;19:134–6.
Contents lists available at ScienceDirect
Best Practice & Research Clinical Obstetrics and Gynaecology journal homepage: www.elsevier.com/locate/bpobgyn
3
Congenital heart disease in pregnancy Lorna Swan, MB ChB, FRCP, MD, Consultant Cardiologist * Adult Congenital Heart Disease Unit, Royal Brompton Hospital, London SW3 6NP, UK
Keywords: congenital heart disease pregnancy pre-conception counselling
The story of congenital heart disease is one of the major successes of medicine in the last 50 years. Heart conditions previously associated with early death are now successfully treated. Many of these women are now in their child-bearing years wishing to have children of their own. All of these women should be offered comprehensive pre-conception counselling by a dedicated multidisciplinary team. Each woman will present a unique set of cardiac and obstetric challenges that require an individualised assessment of risk and a carefully documented care plan. In this chapter, I describe the most common forms of congenital heart disease and the specific issues that should be assessed before conception. I present a systematic approach to risk stratification and care planning. These lesions range from mild disease with little implications for pregnancy to those with a sizable risk of maternal mortality or complications. I will also discuss fetal risk factors. Ó 2014 Elsevier Ltd. All rights reserved.
Introduction With the successful repair and palliation of many forms of congenital heart disease in childhood, a growing population of people are now surviving into adulthood with even complex cardiac lesions [1]. These people have a desire to live as ‘normal’ lives as possible, and having children is part of their expectations for the future. Congenital heart disease is a rare cause of maternal cardiac mortality; however, a large proportion of women attending pre-pregnancy cardiac obstetric clinics have congenital heart disease [2]. The fact that these women have known cardiac disease enables comprehensive pre-conception counselling and
* Tel.: þ44 (0) 207349 7748; Fax: þ44 (0) 207351 8518. E-mail address: [email protected]. http://dx.doi.org/10.1016/j.bpobgyn.2014.03.002 1521-6934/Ó 2014 Elsevier Ltd. All rights reserved.
496
L. Swan / Best Practice & Research Clinical Obstetrics and Gynaecology 28 (2014) 495–506
optimisation of care to take place [3]. In contrast, many women with acquired heart disease often present for the first time during pregnancy. Unsurprisingly, most maternal cardiac fatalities occur within this group [4]. It is difficult to establish precisely the extent of maternal morbidity associated with congenital heart disease. In one of the largest studies on cardiac maternal morbidity [5], congenital heart disease was not labelled as a separate category. The small number of participants with congenital heart disease were listed under those with valve disease. It has been hypothesised that improved pre-conception counselling and antenatal care have led to an improvement in maternal outcomes in congenital heart disease compared with other forms of maternal cardiac disease [6]. A wide spectrum of congenital heart lesions exists, ranging from the benign lesion with no effect on longevity to life-shortening conditions that may be highly symptomatic. Some women may present with a cardiac lesion that has a unique anatomy and physiology, and therefore preconception advice and management plans must be tailored to the individual patient. It is understandable that the evidence base for practice is rather patchy in this heterogenous population, and many of the treatment recommendations are based on clinical consensus [7]. It is, therefore, essential that these women are cared for by a team of experienced clinicians in a multi-disciplinary environment [8].
Principles of pre-conception counselling Preconception counselling should be offered to all women with congenital heart disease who are of child-bearing age. This advice must be given by a specialist multi-disciplinary team with both cardiac and obstetric input. The advice given should be tailored to the unique anatomy and physiology of each particular women. The key components of comprehensive counselling are presented in Table 1. Several simple scoring systems have been developed to assist clinicians in their attempts to effectively risk stratify women contemplating pregnancy. The most commonly used of these are the Cardiac Disease in Pregnancy (CARPREG) score and the ZAHARA (Zwangerschap bij Aangeboren
Table 1 World Health Organization risk groups for people with congenital heart lesions.a WHO risk group I No detectable increased risk of maternal mortality, and no or mild increase in morbidity. Uncomplicated mild lesions. small patent duct or mild pulmonary stenosis. Successfully repaired simple lesions. WHO risk group II (if uncomplicated). Small increased risk of maternal mortality or moderate increase in morbidity. Unrepaired atrial septal or ventricular septal defect. Repaired Tetralogy. WHO risk group II-III (depends on individual patient). Lesions with mild ventricular dysfunction. Native or tissue valve disease (most). Repaired coarctation. WHO risk group III Significantly increased risk of maternal mortality or severe morbidity. Mechanical valves. Systemic right ventricle. Fontan circulation. People with cyanosis and other complex lesions. WHO risk group IV Extremely high risk of maternal mortality or severe morbidity; pregnancy contraindicated. Pulmonary hypertension. Severe systemic ventricular dysfunction. Severe left heart obstruction (including coarctation). a
Adapted from Thorne et al. [30]; WHO, World Health Organization.
L. Swan / Best Practice & Research Clinical Obstetrics and Gynaecology 28 (2014) 495–506
497
Table 2 Pre-pregnancy counselling check list. Maternal risks What are the CARPREG, ZAHARA and modified WHO scores? What is current functional class? Cardiac symptoms? Is there a risk of arrhythmia? Are there any pacing or device issues? Is there a risk of ventricular dysfunction? Is cyanosis an issue? Thrombotic and bleeding risks? Is the pulmonary artery pressure normal? Are there obstructive lesions? Is there a risk of coronary ischaemia? Is there a risk of dissection or aortic rupture? Is there an increased risk of hypertension? Are there drugs that need to be changed or discontinued? Are there other lifestyle issues? Is the patient a smoker? Are there any specific obstetric risks? Are there any fertility issues? Issues about long-term prognosis? Fetal risks Risk due to maternal low cardiac output? Risk due to maternal cyanosis? Risk due to maternal medication? Risks due to maternal lifestyle and smoking? Risk of prematurity or growth restriction? Genetic and recurrence risks?
Hartafwijking) score (Table 2) [9,10]. Although far from comprehensive, these scoring systems offer additional tools to approximate risk. An alternative scale that is also informative is the modified World Health Organization pregnancy classification. This has four categories of risk from class I (little additional risk from pregnancy) to class IV (pregnancy is extremely high risk and should be considered contraindicated) [11]. Determinants of fetal outcome in congenital heart disease Most research on congenital heart disease has focused on maternal outcomes in pregnancy. A key determinant of fetal outcome is maintaining maternal health. Some maternal features are a specific risk to the fetus. These include maternal symptoms, cyanosis, anticoagulation, cigarette smoking, multiple gestation and left heart obstruction [9]. In addition, maternal drug treatments may also adversely affect the fetus; the most common of these are oral anticoagulants [12] and beta-blockers [13]. An important component of pre-pregnancy counselling is assessing the potential fetal affects of cardiac drugs. Ideally, women should be taking a minimum number of essential drugs, and, where possible, drugs with safety concerns should have been discontinued or substituted by alternatives. Risk of recurrence of congenital heart defects in offspring Many congenital heart defects have a familial basis. The live birth risk of congenital heart disease is 0.8% for the general population [14]; in mothers with congenital heart disease, this risk is in the region of 3–5% [15]. This average, however, covers a divergent group of conditions. In a few circumstances, an autosomal dominant inheritance pattern exists (with a 50% recurrence risk). This group includes patients with Di George syndrome (22q11 deletion). These women often have conotruncal lesions, including Tetralogy of Fallot and truncus arteriosus. All women with these lesions should be offered genetic testing before pregnancy [16]. Other sub-groups of congenital heart disease have a higher heritability than the average 3–5% value often quoted. These include bicuspid aortic valve disease, atrioventricular septal defect, and atrial septal defect [17]. For all of these conditions, an estimation of recurrence risk should be individualised to the woman’s lesion and their family history. All pregnant
498
L. Swan / Best Practice & Research Clinical Obstetrics and Gynaecology 28 (2014) 495–506
women with a personal or partner history of congenital heart disease should be offered a detailed fetal echocardiogram at 16–23 weeks’ gestation [18]. Defects not detected before pregnancy It is unusual for congenital heart defects to be detected for the first time during pregnancy. A whole range of detects, however, can be been discovered either during routine antenatal review or when the woman presents with an acute complication during pregnancy. A sub-group of these women may have been told they had a heart defect in childhood, but then were either lost to cardiac follow up or never had an opportunity for a full cardiac assessment. Immigrants sometimes fall into this latter category [8]. The most common defects detected in pregnancy include atrial septal defects and mild valve lesions. Women with no previous history of heart disease do not have the opportunity to receive preconception counselling; the most effective way of managing these women is to have pre-defined referral pathway to specialist multi-disciplinary care, which can be triggered as soon as a suspected abnormality is detected. Principles governing delivery Many clinical teams have strong views about the merits and limitations of vaginal delivery compared with caesarean section. These views are not evidence based, but rely on personal experience and anecdote. In congenital heart disease, the mode of delivery is rarely determined by cardiac features alone, and is more frequently an obstetric decision. The gestational age of the fetus will also be an important contributing factor. Vaginal delivery, particularly when accompanied by effective regional anaesthesia, is associated with less haemodynamic change than caesarean section. Thrombosis and bleeding are also less problematic. An elective caesarean section delivery may have logistical advantages. Delivery planning should be a multi-disciplinary (e.g. obstetrician, cardiologist, anaesthetist, neonatologist and patient) decision, and plans should be made and communicated well in advance of the due date. In women with congenital heart disease, it is particularly important that the extended team understand the patient’s anatomy and physiology, and are aware of the normal resting variables, such as oxygen saturations. Care should be taken to identify obstetric drugs that may cause cardiac instability, and limitations should be set regarding the duration of the second stage if contemplating a vaginal delivery. Additional prophylactic antibiotics are not required over and above normal obstetric practice [19]. Specific congenital heart disease lesions In the following section, I discuss several specific forms of congenital heart disease. This is not an exhaustive list and, a wide variety of pathologies exist within each category. For example, a woman with repaired Tetralogy of Fallot may have a near normal heart, but may have a complex lesion with aortopulmonary collateral arteries and cyanosis. As stated previously, each woman will require a unique assessment and management plan. Septal defects One of the most common forms of congenital heart disease is the group of lesions known as septal defects. These include defects of the atrial septum (atrial septal defect [ASD] or patent foramen ovale [PFO]) and of the ventricular septum (ventricular septal defect [VSD]). This group also includes the more complex lesion – the atrioventricular septal defect (AVSD). Most septal defects will be detected in childhood. The exception to this is the isolated atrial septal defect. Women with ASDs may have few clinical signs and remain asymptomatic until presenting for the first time in pregnancy. The principles guiding the management of all of these septal defect lesions are similar, and focus on the haemodynamic significance of the defect.
L. Swan / Best Practice & Research Clinical Obstetrics and Gynaecology 28 (2014) 495–506
499
Defects of the atrial septum Atrial septal defects are associated with a left to right shunt across the atrial septum. The degree of shunting will depend on the size of the defect and the compliance of the right heart. A typical secundum ASD will result in volume loading of the right heart, with dilatation of the right atrium and right ventricle. The function of the right ventricle is usually well preserved but may become impaired over time. Intracardiac shunting results in excessive pulmonary blood flow. With an unoperated atrial septal defect, a full pre-pregnancy or pregnancy assessment will include an assessment of the right ventricular volume loading and function. A dilated right ventricular may be associated with effort intolerance. Poor right ventricular function is unusual, but would be a concern if present. Another key component that needs to be assessed is the pulmonary artery pressure and pulmonary vascular resistance. This will be the major determinant of maternal outcome. In atrial septal defects, the pulmonary artery pressure is often elevated because of increased pulmonary blood flow, but pulmonary vascular resistance is rarely significantly elevated. Each woman should also have their arrhythmia profile assessed. Atrial septal defects are associated with an increased risk of atrial arrhythmias [20], and these may be more troublesome during pregnancy. If these are short or asymptomatic, then they rarely need treatment. Atrial septal defects and PFOs may be associated with a risk of paradoxical embolism in pregnancy [21]. This is compounded by the hypercoagulable state associated with pregnancy. Women with additional risk factors, or those who have had a previous embolic event, may need to be given antiplatelet or anticoagulants during pregnancy and the puerperium. An ASD can be repaired either surgically or using percutaneous devices. The repaired defect is rarely a challenge to pregnancy, although arrhythmia and issues of pulmonary vascular disease still need to be fully assessed. The unrepaired defect rarely needs to be considered for closure during pregnancy, as it is well tolerated and generally women are asymptomatic. A PFO is present in up to 20% of the population. It is of no haemodynamic significance in most cases, although when associated with other cardiac defects such as pulmonary stenosis, it may lead to right to left shunting of blood across the PFO. In a small select group of women, a PFO may be a risk factor for stroke. It is only in this limited setting that a PFO may be important during pregnancy. If the PFO has not been closed, it may be of value to increase the anticoagulant regimen in a woman who has had a previous cryptogenic stroke. Atrioventricular septal defect The atrioventricular septal defect is a more complex lesion associated with abnormalities of the atrioventricular valves and both the atrial and ventricular septum. The simplest of this spectrum of disorders is the isolated primum ASD; the most complex, a complete AVSD, involves atrial and ventricular septal defects and a common atrioventricular valve. In women with either unoperated or operated AVSD, the key components that need to be considered before pregnancy and during pregnancy are the status of the atrioventricular valves because regurgitation is common in ventricular function and the pulmonary artery pressures. An unoperated AVSD may result in Eisenmenger physiology (see below). Ventricular septal defects In contrast to an ASD, a ventricular septal defect is often detected on routine examination, as it is invariably associated with a loud systolic murmur. For this reason, most significant defects are diagnosed and surgically treated in childhood. Device closure is possible but less common. Most unoperated VSDs in adulthood are small and restrictive, with normal pulmonary artery pressure. Paradoxical embolism is rare, as it has a large left to right shunt and pressure gradient. Women with either unoperated VSDs or with late repair may have associated pulmonary vascular disease (see below). Women with an uncomplicated repaired VSD or small restrictive defects should have a normal obstetric course and will require little additional support.
500
L. Swan / Best Practice & Research Clinical Obstetrics and Gynaecology 28 (2014) 495–506
The other common intra-cardiac shunt is the patent ductus arteriosus (PDA). This should be assessed in a manner similar to the VSD with the key issues of left ventricular volume loading and the detection of pulmonary hypertension. In adults, unoperated PDAs are unusual but may be of varying severities from a small insignificant defect to those with Eisenmenger physiology. When assessing a woman with a PDA, it is important to look for ‘differential cyanosis’ – that is near normal saturations in the upper body but cyanosis in the lower limbs. Tetralogy of Fallot Tetralogy of Fallot is one of the most commonly repaired congenital lesions seen in adulthood. Tetralogy is characterized by a large VSD, override of the aorta and obstruction to pulmonary blood flow either at the valve or sub-valvar. Surgical repair includes closing the VSD with a patch and opening up the right ventricular outflow tract and pulmonary valve. Unoperated Tetralogy is rare in adulthood, and is associated with cyanosis and severe right ventricular hypertrophy. In operated individuals, residual lesions are common; these include residual pulmonary valve disease (usually post-surgical pulmonary regurgitation) and residual VSDs. Pulmonary regurgitation is a common finding after repair of Tetralogy, and more than 70% of women will go on to need replacement of their pulmonary valve later in life. Chronic pulmonary regurgitation leads to progressive dilatation of the right ventricle, and eventually impairment of right ventricular function. Women who are contemplating pregnancy should be fully assessed before pregnancy, and may need valve pulmonary replacement before conception. Women who become pregnant with severe pulmonary regurgitation further dilate their right ventricles and may develop effort intolerance or arrhythmia [22,23]. Chronic pulmonary regurgitation is also associated with intrauterine growth restriction [24]. Pulmonary stenosis Isolated pulmonary stenosis (or pulmonary stenosis in the setting of repaired Tetralogy) is usually well tolerated. Over time, however, progressive right ventricular hypertrophy and dilatation of the right atrium (RA) may occur. Again, atrial arrhythmia and effort intolerance may occur. Overt right heart failure is rare. Women with pulmonary stenosis tend to have a good pregnancy outcome. Valvar pulmonary stenosis may be amenable to balloon valvuloplasty but this is rarely required during pregnancy [25]. Many women with more complex congenital heart defects have been repaired using right ventricular to pulmonary artery conduits. These are assessed in the same way as a native pulmonary valve. Echocardiography and cardiac magnetic imaging may both be required to assess conduit function and the right ventricle fully [26]. Left ventricular outflow tract obstruction Aortic valve disease will be discussed in another section. In women contemplating pregnancy, however, most aortic valve disease is congenital in origin. Part of congenital anomaly may include a deficiency in the number of aortic valve cusps (unicuspid or more commonly a bicuspid valve). These valves may be either stenotic, regurgitant, a combination of both, or have normal function. Prepregnancy assessment must include a full assessment of the haemodynamic significance of the valve lesion and the presence or absence of aortic dilatation. In general, aortic regurgitation is well tolerated during pregnancy. Again, the key issue is the size and function of the left ventricle. In women with aortic stenosis, a full assessment will include an echocardiogram, electrocardiogram, exercise tolerance test, and cardiac magnetic resonance scan. Concerning features would include the presence of symptoms, resting or exercise stress test changes on the electrocardiogram, the presence of significant left ventricular hypertrophy (LVH), and left atrium dilatation. A pre-conception exercise test may provide additional prognostic information. A good effort capacity with an appropriate blood pressure and heart rate response would be reassuring. A drop of blood pressure on exercise may highlight a women who might struggle to increase her cardiac output during pregnancy.
L. Swan / Best Practice & Research Clinical Obstetrics and Gynaecology 28 (2014) 495–506
501
In general, an aortic gradient on echo of less than 64 mmHg is usually well tolerated. Over this level, the other features listed above become important. The presence of concerning features or a high aortic valve gradient should trigger a discussion about valve surgery before pregnancy. If a woman with significant aortic stenosis does become pregnant, then an attempt to stratify the risks associated with continuing with the pregnancy should be made. Women with high-risk features may wish to consider termination of pregnancy. If isolated valvar stenosis with minimal regurgitation is diagnosed, then ballooning the valve if the woman shows signs of instability may be an option [27]. Surgical replacement of the aortic valve during pregnancy is possible in extreme circumstances, although cardiopulmonary bypass is associated with a high rate of fetal loss [28]. Women with less extreme compromise are best managed conservatively. Beta-blockers may play some role if a large dynamic component is associated with left ventricular outflow tract obstruction. Diuretics may be needed if symptoms of high left atrial pressure develop (e.g. breathlessness and dry cough). Bed rest and monitoring of fetal growth may be needed in the third trimester in women who become more symptomatic. Early delivery may be necessary in women who are unstable. The principles that guide delivery will be to minimise the haemodynamic effect of the fixed aortic stenotic lesion. The ideal mode of delivery is controversial but vaginal delivery under a low-dose epidural is proposed by many. Drugs that lead to vasodilatation should be avoided, and the second stage should be assisted in women with all but mild stenosis. Coarctation of the aorta Coarctation of the aorta is usually repaired in the neonatal period. Various surgical techniques have been used in the past, including several techniques now known to be associated with late complications. The most concerning of these was the Dacron patch repair, which is often associated with late false aneurysms. Unoperated coarctation can present in pregnancy with severe hypertension. Management of the hypertension may be problematic, as a large gradient may cross the coarctation. Reduction of maternal upper body blood pressure may compromise the fetoplacental unit. Stenting of the coarctation can be carried out during pregnancy if the risk of maternal stroke or heart failure due to uncontrolled hypertension is a concern [29]. In women who have undergone surgery, a key component of maternal outcome will be the detection and timely treatment of hypertension. In women with a subclavian flap repair of coarctation, left arm pulses may be absent, and blood pressure should be taken in the right arm. Hypertension during pregnancy is usually effectively treated with beta-blockers, but other anti-hypertensive agents can be used if needed to maintain normotension, including calcium antagonists and methyldopa. Fetal growth should be monitored in the third trimester. In women with a known coarctation repair site aneurysm, pregnancy would be a risk factor for rupture, and should therefore be delayed until it is treated surgically or treated by percutaneous replacement of a covered stented. If the original type of surgical repair is unknown, then a pre-pregnancy (or pregnancy) cardiac magnetic resonance scan should be carried out. Most women with a coarctation will also have a bicuspid aortic valve, and some will have dilatation of the ascending aorta. Transposition of the great arteries Transposition is a group of conditions that have ‘dis-cordance’ between the ventricles and the great arteries (Fig. 1) [30]. In both subtypes (L-transposition [congenitally corrected transposition] and in simple D-transposition) the right ventricle is connected to the aorta and is the systemic pump. In congenitally corrected transposition, other lesions may be associated (e.g. VSD, pulmonary valve stenosis, or an Ebstein-like abnormality of the tricuspid valve). The crucial determinant of outcome is the function of the systemic right ventricle. The principles that guide the management of these women are the same as for other forms of ventricular dysfunction. Women with severe systemic right ventricular dysfunction should be counselled against pregnancy, as the risk of developing heart failure is high.
502
L. Swan / Best Practice & Research Clinical Obstetrics and Gynaecology 28 (2014) 495–506
Fig. 1. Transposition of the great arteries and its various forms in adulthood. LV, left ventricle; RA, right atrium; RV, right ventricle; RV*, signified lesions with a RV supporting the systemic circulation.
In contrast with congenitally corrected transposition, women with dextro-transposition of the great arteries require life-saving surgery in the first few days of life. Historically, this was an atrial switch (Mustard or Senning) operation. These women have an intra-atrial repair to redirect the venous inflow into the heart. The right ventricle remains in the sub-systemic position, and, again, its function is the main determinant of outcome. Women with atrial switch operations are also prone to arrhythmias, which may be exacerbated by pregnancy. Nowadays, the transposition of the great arteries is repaired by the arterial switch operation, which became the standard surgical repair from the 1980s onwards. In this operation, the two great arteries are ‘switched’. In general, this leaves a heart with few surgical sequelae that pose an issue during pregnancy. The other major surgical technique used was the Rastelli operation, using a right ventricular to pulmonary artery conduit, and a patch repair of the VSD tunnelling the left ventricular to the aorta. For women with a Rastelli, the main focus before pregnancy is function of the right ventricle to pulmonary artery conduit, which over time may become obstructed or regurgitant. Function of the left and right ventricles should also be assessed.
Cyanotic cardiac defects (without pulmonary hypertension) A variety of congenital heart defects are associated with a degree of systemic cyanosis. This can range from cyanosis only evident on exercise to profound resting desaturation and with oxygen saturations 70 mg/l or over. Chronic cyanosis has an effect on many organ systems, all of which may be important during pregnancy. It is associated with an erythrocytosis (isolated high haemoglobin level), low platelets and clotting abnormalities, and haemoglobin may be in excess of 20 g/dL in some women.
L. Swan / Best Practice & Research Clinical Obstetrics and Gynaecology 28 (2014) 495–506
503
Pregnant women may be more prone to bleeding and thrombotic events. Cyanosis also increases the risk of infections, including atypical infections and cerebral abscess. One of the more challenging components of desaturation is its affect on fetal outcome. When resting oxygen saturations fall below 85%, the chance of a live birth is greatly diminished at less than 12% [31]. Early pregnancy loss and intrauterine death both increase in line with decreasing oxygen saturations and increasing maternal haemoglobin levels. Oxygen therapy and bed rest may be used to try to improve fetal growth, but growth restriction and preterm delivery remain common. Eisenmenger physiology Eisenmenger physiology is a form of severe pulmonary hypertension secondary to a long-standing left to right shunt. With time, the pulmonary vascular resistance rises and eventually becomes equal to the systemic pressure. As a consequence, the left to right intra-cardiac shunt decreases and finally reverses leading to cyanosis. In addition to the risks of cyanosis, the woman also has severe pulmonary vascular disease. Eisenmenger syndrome is associated with a high maternal and fetal risk, and women with Eisenmenger syndrome should be advised against pregnancy [32]. Although treatment has improved, maternal mortality remains in excess of 20% [33]. If a woman presents in early pregnancy, then termination should be considered, although the termination itself may be associated with maternal morbidity and even mortality [34]. If a woman with Eisenmenger syndrome chooses to continue with a pregnancy, oxygen therapy, aggressive use of pulmonary vasodilator therapies, and care by a specialist multidisciplinary team, may help to minimise mortality [35]. The major causes of death in this population are right ventricular failure, pulmonary hypertension crisis, arrhyththmia, and stroke. Specialist counselling and contraceptive advice is essential among women with Eisenmenger syndrome. Ebstein anomaly A rarer form of congenital heart disease is the Ebstein anomaly. This is an abnormality of the right heart, with displacement of the tricuspid valve and tricuspid regurgitation. Common associated lesions are a PFO or ASD atrial arrhythmias secondary to accessory condition pathways. People with Ebstein anamoly are frequently cyanosed. The factors predicting maternal and fetal outcome are the presence of severe tricuspid regurgitation, right ventricular function, the degree of cyanosis, and a history of arrhythmia. In the absence of these adverse features, pregnancy is usually well
Fig. 2. Maternal and fetal implications of a Fontan Circulation. IVC, inferior vena cava; LA, left atrial; RA, right atrial; RPA, right pulmonary artery; SVC, superior vena cava.
504
L. Swan / Best Practice & Research Clinical Obstetrics and Gynaecology 28 (2014) 495–506
tolerated with a good outcome [36]. Severe Ebstein anomaly, however, should be repaired before pregnancy. The Fontan operation and other single ventricles The Fontan operation was developed in the 1970s to provide a surgical solution for women whose anatomy was such that biventricular circulation could not be created. In the Fontan operation and its modern iterations, the systemic venous return (the superior and inferior vena cava) is anastomosed directly on to the pulmonary arteries. The effective single ventricle supports the systemic circulation. A proportion of women with single ventricle physiology may never have been considered for a Fontan operation – these were either women with a ‘balanced’ circulation with a large VSD and some form of limitation to pulmonary blood flow (e.g. either pulmonary stenosis or a surgically placed pulmonary artery band) or with unrestricted pulmonary blood flow and secondary pulmonary hypertension. In both of these latter groups, severe cyanosis will be present. Women with a Fontan circulation are at risk of thrombus formation, as venous return is slow flowing. Those with older versions of the Fontan (e.g. the right atrial-to-pulmonary artery connection) will usually be fully anticoagulated; those with more efficient total cavopulmonary connections will be given antiplatelet therapy only. During pregnancy, the anticoagulant regimen will need to be escalated, and many women are treated with low molecular weight heparins. The Fontan circulation presents a unique physiology with important implications for pregnancy and delivery [37]. For effective pulmonary blood flow, the patient must have a sufficient filling pressure. Periods of hypotension or bleeding will be poorly tolerated. Atrial arrhythmias are common in this patient group and, if sustained, they are considered to be a medical emergency and require electrical cardioversion, usually under general anaesthesia with external pacing pads in place. If cardioversion is required in pregnancy, the fetal heart rate should be checked before and after. Fetal bradycardias have been documented [38]. Meticulous fluid balance is required at the time of delivery, and great care should to be taken to avoid anything that may increase pulmonary artery pressure or cause a drop in filling pressures. Again cyanosis is common in women with a Fontan circulation, although saturations are usually above 85%. Intrauterine growth restriction and preterm delivery are common (Fig. 2). Conclusion Increasing numbers of women with repaired and palliated congenital heart disease are now of child-bearing age. Counselling and optimally managing these women during pregnancy requires a team of multi-disciplinary clinicians and established referral pathways.
Practice points An increasing number of women with congenital heart disease are reaching child-bearing age, and all of them should be offered advice regarding contraception, pregnancy, and recurrence risk. Congenital heart disease is fortunately a rare cause of maternal death but it does present management issues for both the mother and the fetus. Pre-conception advice and pregnancy planning needs to be tailored to the individual patient who may have a unique anatomy and physiology. Multi-disciplinary care is particularly important in this area where the evidence base is sparse.
L. Swan / Best Practice & Research Clinical Obstetrics and Gynaecology 28 (2014) 495–506
505
Research agenda Many questions on pregnancy and congenital heart disease remain unanswered. The research opportunities are extensive and have the potential to address clinical questions that will directly affect patient care. These include:
Further investigation of the effect of pregnancy on ventricular function. Research into the effect of pregnancy on long-term maternal cardiac outcomes. Research into the fetal risks of newer anticoagulant drugs. Further study into the familial and genetic determinants of congenital heart disease.
References [1] Opotowsky AR, Siddiqi OK, Webb GD. Trends in hospitalizations for adults with congenital heart disease in the U.S. J Am Coll Cardiol 2009;54:460–7. [2] Valente AM, Landzberg MJ, Gianola A, et al. Improving heart disease knowledge and research participation in adults with congenital heart disease (The Health, Education and Access Research Trial: HEART-ACHD). Int J Cardiol 2013;168:3236– 40. [3] Curry R, Swan L, Steer PJ, et al. Cardiac disease in pregnancy. Curr Opin Obstet Gynecol 2009;21:508–13. *[4] Malhotra S, Yentis SM. Reports on Confidential Enquiries into Maternal Deaths: management strategies based on trends in maternal cardiac deaths over 30 years. Int J Obstet Anesth 2006;15:223–6. *[5] Huisman CM, Zwart JJ, Roos-Hesselink JW, et al. Incidence and predictors of maternal cardiovascular mortality and severe morbidity in The Netherlands: a prospective cohort study. PLoS One 2013;8:e56494. *[6] Cantwell R, Clutton-Brock T, Cooper G, et al. Saving mothers’ lives: reviewing maternal deaths to make motherhood safer: 2006–2008. The Eighth Report of the Confidential Enquiries into Maternal Deaths in the United Kingdom. BJOG 2011; 118(Suppl. 1):1–203. *[7] Regitz-Zagrosek V, Blomstrom Lundqvist C, Borghi C, et al. ESC Guidelines on the management of cardiovascular diseases during pregnancy: the Task Force on the Management of Cardiovascular Diseases during Pregnancy of the European Society of Cardiology (ESC). Eur Heart J 2011;32:3147–97. [8] Gelson E, Gatzoulis MA, Steer P, et al. Heart disease: why is maternal mortality increasing? BJOG 2009;116:609–11. *[9] Siu SC, Sermer M, Colman JM, et al. Prospective multicenter study of pregnancy outcomes in women with heart disease. Circulation 2001;104:515–21. *[10] Drenthen W, Boersma E, Balci A, et al. Predictors of pregnancy complications in women with congenital heart disease. Eur Heart J 2010;31:2124–32. [11] Roos-Hesselink JW, Duvekot JJ, Thorne SA. Pregnancy in high risk cardiac conditions. Heart 2009;95:680–6. [12] Mehndiratta S, Suneja A, Gupta B, et al. Fetotoxicity of warfarin anticoagulation. Arch Gynecol Obstet 2010;282:335–7. [13] Gelson E, Curry R, Gatzoulis MA, et al. Effect of maternal heart disease on fetal growth. Obstet Gynecol 2011;118:364. [14] van der Linde D, Konings EE, Slager MA, et al. Birth prevalence of congenital heart disease worldwide: a systematic review and meta-analysis. J Am Coll Cardiol 2011;58:2241–7. *[15] Burn J, Brennan P, Little J, et al. Recurrence risks in offspring of adults with major heart defects: results from first cohort of British collaborative study. Lancet 1998;351:311–6. [16] Chessa M, Butera G, Bonhoeffer P, et al. Relation of genotype 22q11 deletion to phenotype of pulmonary vessels in tetralogy of Fallot and pulmonary atresia-ventricular septal defect. Heart 1998;79:186–90. [17] Fesslova V, Brankovic J, Lalatta F, et al. Recurrence of congenital heart disease in cases with familial risk screened prenatally by echocardiography. J Pregnancy 2011;2011:368067. *[18] Gill HK, Splitt M, Sharland GK, et al. Patterns of recurrence of congenital heart disease: an analysis of 6,640 consecutive pregnancies evaluated by detailed fetal echocardiography. J Am Coll Cardiol 2003;42:923–9. *[19] Baumgartner H, Bonhoeffer P, De Groot NM, et al. ESC Guidelines for the management of grown-up congenital heart disease (new version 2010). Eur Heart J 2010;31:2915–57. [20] Gatzoulis MA, Freeman MA, Siu SC, et al. Atrial arrhythmia after surgical closure of atrial septal defects in adults. N Engl J Med 1999;340:839–46. [21] Daehnert I, Ewert P, Berger F, et al. Echocardiographically guided closure of a patent foramen ovale during pregnancy after recurrent strokes. J Interv Cardiol 2001;14:191–2. [22] Uebing A, Arvanitis P, Li W, et al. Effect of pregnancy on clinical status and ventricular function in women with heart disease. Int J Cardiol 2010;139:50–9. [23] Balci A, Drenthen W, Mulder BJ, et al. Pregnancy in women with corrected tetralogy of Fallot: occurrence and predictors of adverse events. Am Heart J 2011;161:307–13. [24] Gelson E, Gatzoulis M, Steer PJ, et al. Tetralogy of Fallot: maternal and neonatal outcomes. BJOG 2008;115:398–402. [25] Loya YS, Desai DM, Sharma S. Mitral and pulmonary balloon valvotomy in pregnant patients. Indian Heart J 1993;45:57–9. [26] Babu-Narayan SV, Kilner PJ, Li W, et al. Ventricular fibrosis suggested by cardiovascular magnetic resonance in adults with repaired tetralogy of fallot and its relationship to adverse markers of clinical outcome. Circulation 2006;113:405–13.
506
L. Swan / Best Practice & Research Clinical Obstetrics and Gynaecology 28 (2014) 495–506
[27] Myerson SG, Mitchell AR, Ormerod OJ, et al. What is the role of balloon dilatation for severe aortic stenosis during pregnancy? J Heart Valve Dis 2005;14:147–50. [28] Chandrasekhar S, Cook CR, Collard CD. Cardiac surgery in the parturient. Anesth Analg 2009;108:777–85. [29] Assaidi A, Sbragia P, Fraisse A. Transcatheter therapy for aortic coarctation with severe systemic hypertension during pregnancy. Catheter Cardiovasc Interv 2013;82:556–9. [30] Thorne S, MacGregor A, Nelson-Piercy C. Risks of contraception and pregnancy in heart disease. Heart 2006;92:1520–5. [31] Presbitero P, Somerville J, Stone S, et al. Pregnancy in cyanotic congenital heart disease. Outcome of mother and fetus. Circulation 1994;89:2673–6. [32] Yentis SM, Steer PJ, Plaat F. Eisenmenger’s syndrome in pregnancy: maternal and fetal mortality in the 1990s. Br J Obstet Gynaecol 1998;105:921–2. [33] Bedard E, Dimopoulos K, Gatzoulis MA. Has there been any progress made on pregnancy outcomes among women with pulmonary arterial hypertension? Eur Heart J 2009;30:256–65. [34] Satoh H, Masuda Y, Izuta S, et al. Pregnant patient with primary pulmonary hypertension: general anesthesia and extracorporeal membrane oxygenation support for termination of pregnancy. Anesthesiology 2002;97:1638–40. *[35] Kiely DG, Condliffe R, Webster V, et al. Improved survival in pregnancy and pulmonary hypertension using a multiprofessional approach. BJOG 2010;117:565–74. [36] Katsuragi S, Kamiya C, Yamanaka K, et al. Risk factors for maternal and fetal outcome in pregnancy complicated by Ebstein anomaly. Am J Obstet Gynecol 2013;209:452.e1–6. [37] Drenthen W, Pieper PG, Roos-Hesselink JW, et al. Pregnancy and delivery in women after Fontan palliation. Heart 2006; 92:1290–4. [38] Tromp CH, Nanne AC, Pernet PJ, et al. Electrical cardioversion during pregnancy: safe or not? Neth Heart J 2011;19:134–6.
