Clinical Opinion
ajog.org
OBSTETRICS
The multidisciplinary approach to the care of the obese parturient Neda Ghaffari, MD; Sindhu K. Srinivas, MD, MSCE; Celeste P. Durnwald, MD
Maternal obesity in pregnancy is associated with increased maternal and fetal risks. Pregnancy management should include counseling, screening, and optimization of maternal health, increased fetal surveillance, and preparation for parturition. A multidisciplinary approach should be implemented including collaboration from obstetricians, nutritionists, anesthesiologists, social workers, and neonatologists to optimize perinatal outcomes. Pregnancy is an ideal window of opportunity to influence both the patient’s long-term health and the health of the offspring. Key words: adverse pregnancy outcomes, fetal overgrowth, obesity
I
n the United States, the prevalence of obesity is increasing. In 2012, 36.5% of US adult women reported a body mass index (BMI) of 30 kg/m2 or greater, which classified them as obese.1 Furthermore, more than 50% of all pregnant women are overweight or obese.2 Maternal obesity connotes an increased risk of the following perinatal complications: gestational hypertension, preeclampsia, gestational diabetes, cesarean delivery,3 miscarriage,4 anesthesia difficulties,5 failed induction of labor, postpartum hemorrhage, infectious morbidity, and venous thromboembolism.6 Additionally, infants born to obese women are at increased risk of congenital anomalies, prematurity, stillbirth, macrosomia with possible birth injury,
From the Maternal and Child Health Research Program, Department of Obstetrics and Gynecology, Center for Research on Reproduction and Women’s Health, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA. Received Dec. 9, 2014; revised Feb. 20, 2015; accepted March 1, 2015. The authors report no potential conflicts of interest. Corresponding author: Neda Ghaffari, MD. [email protected] 0002-9378/$36.00 Published by Elsevier Inc. http://dx.doi.org/10.1016/j.ajog.2015.03.001
and childhood obesity.7,8 Maternal obesity has long-term health implications for the mother including the development of metabolic and cardiovascular disease.9 The management of obese women can be challenging for clinicians and hospital systems. Obese women require more health care resources and additional equipment to provide the necessary and appropriate prenatal and delivery care. This ultimately leads to increased health care costs.10 Although the focus of this review is to provide guidelines for a multidisciplinary approach to the care of the obese parturient, studies regarding the efficacy of these interventions are limited. A pragmatic approach to comprehensive care of obese women includes specialized nursing care, anesthesia, and obstetrical staff as well as nutritional and social work support. By using an interdisciplinary approach to health care, providers can not only optimize care related to the current pregnancy but also discuss the long-term implications of obesity on a woman’s future health, thereby creating a framework for change.
Classification of obesity The American Congress of Obstetricians and Gynecologists (ACOG) endorses the World Health Organization’s and the National Institutes of Health’s definitions for obesity: underweight as a BMI
318 American Journal of Obstetrics & Gynecology SEPTEMBER 2015
of 18.5 kg/m2, normal weight as a BMI of 18.5e24.9 kg/m2, overweight as a BMI of 25.0e29.9 kg/m2, and obesity as a BMI of 30 kg/m2 or greater. Obesity can be further subdivided into class I (30.0e34.9 kg/m2), class II (35.0e39.9 kg/m2), and class III (>40 kg/m2).11,12 The Institute of Medicine reexamined recommendations for gestational weight gain in pregnancy in 2009 based on more women entering pregnancy at heavier BMIs and gaining excess weight during pregnancy. This increases perinatal risks to both the mother and fetus.13 Current recommendations for weight gain in pregnancy based on prepregnancy BMI are listed in Table 1. A common criticism of the newly adopted guidelines is that weight gain is not stratified by class of obesity. Based on expert opinion and clinical judgment, there is no absolute minimum amount of weight gain necessary as long as fetal growth is assessed and is appropriate for the stated gestational age.
Preconception care In reproductive-aged obese women, optimization of pregnancy outcomes should begin with preconception counseling (Table 2). The optimal time for women to improve their health and decrease weight-related complications is prior to pregnancy. Weight management is an essential part of counseling at the time of annual health maintenance. Achieving a normal BMI prior to pregnancy decreases the rate of perinatal complications more than any other intervention during pregnancy, such as minimizing weight gain. Women can often decrease risks of adverse outcomes in pregnancy with modest weight reductions of as little as 10 pounds.14 Women’s health providers of all disciplines should consider offering community health resources for weight loss consultation with a nutritionist.
Obstetrics
ajog.org Health care coverage should focus on these preventative efforts. Realistic goals for weight loss should be set. Additionally, bariatric surgery prior to conception has been shown to improve perinatal outcomes in obese women.15,16 A subset of obese women would benefit from referral for bariatric surgery.17 In general, bariatric surgery is considered for patients with a BMI greater than 40 kg/m2 or a BMI greater than 35 kg/m2 and at least 1 obesity-related comorbidity, most commonly: type 2 diabetes, hypertension, hyperlipidemia, obstructive sleep apnea (OSA), obesityhypoventilation syndrome, or asthma.18 In many centers, including our own, at least 2 months of medical weight management needs to be completed in the bariatric surgery program, and medical comorbidities must be optimized prior to undergoing the operative procedure. If a patient is planning a future pregnancy, she should delay pregnancy following bariatric surgery for 1-2 years to allow for complete weight loss and recovery.19
Health screening for comorbid conditions Obese women should be screened for medical comorbidities before conception or in early pregnancy. This includes screening for type 2 diabetes mellitus, chronic hypertension, cardiac disease, and obstructive sleep apnea.20 Standard screening methods such as the 2 hour oral glucose tolerance test, hemoglobin A1C, and ambulatory blood pressure assessment should be completed. An electrocardiogram (EKG) may be considered in select cases of medical comorbidities, with echocardiogram if EKG findings are suggestive of an abnormality. The Snoring, Tired, Observed, and blood Pressure (STOP) questionnaire should be used to screen for sleep apnea (Table 3). All women should be screened for dyslipidemia at age 45 years, and testing at age 20-45 years should be considered in women with obesity, especially if other risk factors of coronary heart disease (diabetes, previous personal history of coronary heart disease or noncoronary atherosclerosis, family history
Clinical Opinion
TABLE 1
IOM recommendations for weight gain in pregnancy based on prepregnancy BMI BMI, kg/m2
Total weight gain range, lb
Rates of weight gain second and third trimester, lb/wk (mean range)
Underweight
35 kg/m2), and preeclampsia (OR, 1.6; 95% CI, 1.1e2.25 for BMI 30e34.9 kg/m2; OR, 3.3; 95% CI, 2.4e4.5 for BMI >35 kg/m2)3 as well as intrauterine fetal demise (OR, 4.3; 95% CI, 2.0e9.3).27,28 In early pregnancy, screening with an
SEPTEMBER 2015 American Journal of Obstetrics & Gynecology
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Clinical Opinion
Obstetrics
ajog.org
TABLE 2
Key considerations in the care of obese women in pregnancy Phase of pregnancy care
Considerations
Preconception
Document height, weight, BMI Counsel on risks during pregnancy and for long-term maternal health Screen for diabetes with a 2 hour glucose tolerance test or HbA1C Document blood pressure Consider EKG, especially with comorbidities Consider echocardiogram if EKG abnormalities Screen for depression; refer to mental health professional if indicated Screen for obstructive sleep apnea (Table 3); refer to sleep specialist if indicated Consider lipid screening Discuss weight loss and exercise Refer to nutritionist Consider referral to bariatric surgery program Arrange follow-up to track weight loss and review goals
Prenatal care
Document height, weight, and BMI at every visit Discuss weight gain goals per IOM guidelines (Table 1) and address throughout prenatal care Refer to nutritionist Recommend at least 30 minutes of daily exercise Counsel on risks of obesity in pregnancy Recommend first-trimester ultrasound for dating and diagnosis of multiple gestation Early 1 hour GCT Consider baseline EKG (if not done preconceptionally), especially with comorbidities Screen for obstructive sleep apnea (Table 3); refer to sleep specialist if indicated Offer aneuploidy screening and discuss limitations in obesity Schedule anatomical survey at 20 weeks and discuss limitations in obesity Discuss delivery planning Discuss neuraxial anesthesia and set expectations for difficult placement Growth ultrasound at 32 weeks If BMI >40 kg/m2 or per regional guidelines: consider antepartum testing, starting at 32 weeks
Intrapartum care
Induction of labor by obstetric indications or for comorbidities Anesthesia consult early in labor Early epidural placement Establish reliable fetal monitoring Active management of labor with preparedness for cesarean delivery If delivery via cesarean delivery: 1. Decide on incision type and discuss with patient 2. Consider using self-retaining wound retractor 3. Consider increased dose of preoperative antibiotic (cefazolin 3 g IV [weight 120 kg])
Postpartum
Encourage ambulation Consider postpartum chemoprophylaxis in high-risk patients Contraceptive counseling Encourage breast-feeding Establish a plan for postpartum weight loss
BMI, body mass index; EKG, electrocardiogram; GCT, glucose challenge test; HbA1C, hemoglobin A1C; IOM, Institute of Medicine; IV, intravenous. Ghaffari. Multidisciplinary approach to care of obese parturient. Am J Obstet Gynecol 2015.
early 1-hour glucose challenge test as well as a baseline EKG is recommended. Intrapartum complications include difficulty or inability to accurately monitor the fetus in labor, increased risk of failed induction of labor, and cesarean delivery.3 A delivery plan should be made in the office setting and patient expectations for parturition should be
set. Neuraxial anesthesia in labor should be encouraged, and appropriate expectations should be established regarding the possible difficulty in its placement29 and the increased need for replacement to achieve adequate pain relief.30 Postpartum complications, including postpartum hemorrhage, wound disruption, or infection in the event of
320 American Journal of Obstetrics & Gynecology SEPTEMBER 2015
cesarean delivery, and increased risk of venous thromboembolism (VTE) postpartum12 should be reviewed.
Ultrasound Establishing accurate dating of the pregnancy in the first trimester is important. Obese women may have irregular menses due to oligoovulation,
Obstetrics
ajog.org and a first-trimester ultrasound is often needed to determine an estimated date of delivery. Additionally, obesity has been associated with an increased risk of twin gestations31 and congenital anomalies, especially congenital heart defects (OR, 2.0; 95% CI, 1.2e3.4) and open neural tube defects (OR, 3.5; 95% CI, 1.2e10.3).32 To compound this problem, ultrasound detection of anomalies is more difficult in obese women. Evidence from the First- and Second-Trimester Evaluation of Risk trial suggests that there are a greater number of missed fetal ultrasound diagnoses in obese women.33 Maternal obesity is associated with at least a 20% lower detection of fetal anomalies34 and an increased need for repeat imaging to complete the anatomical survey.35 Women should be offered routine aneuploidy screening and counseled regarding the limitations of ultrasound in detection of anomalies based on their BMI. The overall completion rate of the anatomical survey improves with increasing gestational age and may be best at 20e23 weeks.36 In some centers, including our own, the routine anatomical survey is performed at 20 weeks’ gestation with repeat imaging in 2 weeks if suboptimal views are obtained, which is consistent with expert opinion.35 This approach balances improved detection rates with opportunity for the patient to electively terminate a pregnancy if severe defects are identified.
Fetal growth disturbance and risk of stillbirth Obesity is a risk factor for fetal overgrowth.37-39 Prediction of fetal overgrowth remains difficult40 because fetal growth potential is multifactorial and may be affected by comorbid diabetes and gestational weight gain as well as genetic, racial, and ethnic factors.40 Given the increased risk for growth disturbance and inaccuracy of fundal heights in this population, many providers recommend, at minimum, a single growth ultrasound in the third trimester.41 Additional ultrasound surveillance may be indicated if macrosomia is diagnosed or if there is clinical
Clinical Opinion
TABLE 3
STOP questionnairea S
“Do you snore loudly (louder than talking or loud enough to be heard through closed doors)?”
T
“Do you often feel tired, fatigued, or sleepy during daytime?”
O
“Has anyone observed you stop breathing during your sleep?”
P
“Do you have or are you being treated for high blood pressure?”
a
If answer is yes to 2 or more questions, refer to a sleep specialist. Adapted from Chung et al.44
Ghaffari. Multidisciplinary approach to care of obese parturient. Am J Obstet Gynecol 2015.
concern for fetal overgrowth based on increased fundal height. Obese women are also at increased risk for stillbirth, even after adjusting for both maternal age and comorbid conditions such as hypertension and diabetes.42,43 It is not known whether fetal demise in this group is caused by uteroplacental insufficiency. Although the cost-effectiveness of antenatal testing is yet to be proven, such interventions are often used to potentially offset the stillbirth risk, even in the absence of comorbidities. Although more studies are needed to determine the optimal indications for antenatal testing in this population, one approach that the authors support is to recommend antenatal testing in women with a BMI of greater than 40 kg/m2. The risk of stillbirth must be balanced with the risk of failed induction of labor in this population; therefore, the authors advocate for awaiting spontaneous labor in this group without other medical or obstetrical indications for delivery.
Screening for sleep apnea Obesity is a risk factor for sleepdisordered breathing. Sleep disturbance has been linked to inflammation, oxidative stress, endothelial dysfunction, and metabolic dysregulation in the nonpregnant population. Although the literature on OSA during pregnancy is limited, treatment of OSA has been shown to decrease the rates of gestational diabetes mellitus and hypertensive disorders of pregnancy in small studies. Although no screening tool has been validated in a pregnant population, the Berlin, STOP, and Epworth Sleepiness Scales are the most commonly utilized.
The STOP questionnaire has been validated with polysomnography in nonpregnant populations (Table 3).44 It offers a simple, straightforward approach to screening in a busy clinical practice. In general, when screening with the STOP questionnaire, a woman is considered screen positive if affirmative answers are obtained on 2 or more questions. When screening obese women for sleep-disordered breathing, it is optimal to allow adequate time for a formal evaluation and accurate diagnosis because subsequent treatment with continuous positive airway pressure may decrease adverse perinatal outcomes. It may not be cost effective or pragmatic to screen in the third trimester because delivery might occur prior to a complete work-up. Based on available resources and collaboration with sleep medicine specialists, hospital systems can design screening and evaluation algorithms that incorporate a woman’s BMI, comorbid conditions, and the ability to receive adequate treatment. The relationship between obesity, sleep-disordered breathing, and adverse pregnancy outcomes continues to be an active area of research. A large observational study of 10,000 nulliparous women, the Nulliparous Pregnancy Outcomes Study: Monitoring Mothersto-be study (clinical trials identification NCT01322529), will contribute data on sleep breathing, sleep patterns, and sleep quality in selected nulliparous women.
Delivery considerations Equipment Hospital systems, including outpatient and inpatient facilities, need to be adequately equipped to care for and
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Clinical Opinion
Obstetrics
TABLE 4
Specialized medical equipment for the obese gravida Labor room and hospital room equipment
Labor beds and stretchers rated for morbidly obese patients Long exam gloves Long speculums Large blood pressure cuffs Large sequential compression devises Patient lifts Bariatric wheelchairs Seats for waiting room and hospital rooms Consider alternative fetal heart rate monitoring equipment
Operating room equipment
Operating room tables rated for morbidly obese patients Patient lifts Long instrument tray for cesarean section Consider self-retaining retractors
Anesthesia equipment
Long spinal needles and IV cannulas Wedge for patient positioning for intubation Fiberoptic bronchoscope
IV, intravenous. Ghaffari. Multidisciplinary approach to care of obese parturient. Am J Obstet Gynecol 2015.
evaluate obese pregnant women. Labor and delivery units should stock durable medical equipment that will allow for accurate basic obstetric assessments. This includes long examination gloves, long speculums, large blood pressure cuffs, large sequential compression devices, and specialized surgical equipment (Table 4). Patient lifts are often needed in labor and delivery and postpartum units to safely and efficiently transport patients and decrease the rate of work-related injury.45 Table extenders should be available for the operating room table. Bariatric wheelchairs and appropriately sized seats in hospital waiting rooms are recommended. Hospital systems who care for a large proportion of obese women, including our own, have adopted the use of a monitor that utilizes maternal abdominal fetal electrocardiogram signals46 rather than Doppler ultrasound for obese patients, given that intrapartum fetal monitoring can have poor signal quality in obese women.12 Communication The key for safe obstetrical care of medically complicated patients is effective communication among the multidisciplinary team. Appropriate hand-offs and a culture of safety are an integral part of
caring for all pregnant patients, especially in the care of the obese parturient. Direct communication among the nursing staff, obstetricians, and anesthesiologists is recommended from the time of admission, throughout the labor course, and during the postpartum period. It is crucial to discuss maternal BMI during all patient hand-offs and on multidisciplinary rounds. It is helpful to clearly document BMI on hospital admission and nursing assessment forms and the labor and delivery board as well as in the electronic medical record. Many centers use an early anesthesia consult shortly after admission for laboring obese women. Delivery Women who are obese are thought to have slower labor curves than women of normal weight.47,48 Given the challenges with labor induction and augmentation in this population, induction of labor for obesity in isolation is not recommended. However, these women often have other comorbid medical conditions that necessitate labor induction. In cases of abnormal fetal heart tracings, providers must keep in mind that there will be delays in transporting the patient, positioning in the operating room, and obtaining adequate anesthesia.
322 American Journal of Obstetrics & Gynecology SEPTEMBER 2015
ajog.org An approach of active labor management and preparedness for cesarean delivery is recommended; the threshold to call a cesarean delivery for a category II electronic fetal heart rate tracing may be lower in obese patients, given the concern for logistical delays. In the setting of a category III electronic fetal monitoring tracing, a cesarean delivery should be accomplished as expeditiously as feasible.49 If a decision is made to proceed with a cesarean delivery based on maternal or fetal indications, the maternal BMI should be communicated with nursing, anesthesia, and obstetrics providers. An interdisciplinary team discussion should occur once a cesarean delivery is called to communicate salient aspects of the patient’s course, including her BMI. An additional nurse may be needed to help prepare the patient in the operating room or set up the lift and extenders. Anesthetic considerations Obese parturients are at increased risk of anesthesia-related complications such as failed intubation, aspiration, and nonfunctional epidural anesthesia.50 In one study, the initial epidural catheter failed in 42% of obese (obesity class III) patients (compared with 6% in controls; P < .0001), and intubation was characterized as difficult in 6 of 17 obese patients (0 of 8 controls; P ¼ .059).51 Obese patients should be evaluated by an anesthesiologist shortly after admission.52 Airway evaluation should be completed including Mallampati score; mouth opening and neck range of motion and patients with difficult airways should be identified.53 If a patient is expected to be at high risk for anesthetic complications, this should be considered in delivery planning. Depending on institutional resources, it may be reasonable for women deemed to be of significant anesthetic risk or medical comorbidities to undergo cesarean delivery in the main operating rooms in which specialized equipment and staff are available. This should be planned with the multidisciplinary team prior to the patient’s admission to labor and delivery. Obese women are at an increased risk of requiring general
ajog.org anesthesia.6 Therefore, the use of epidural anesthesia should be encouraged and placed early in the labor course should there be a need for cesarean delivery, thus avoiding general anesthesia. During the informed consent process, the patient should be counseled that epidural placement may be difficult29 and there is an increased need for replacement to achieve adequate pain relief.30 It is recommended that anesthesia assessments occur frequently in morbidly obese patients. The functionality and adequacy of regional anesthesia should be checked regularly with a low threshold to replace poorly functioning epidurals. Operating rooms should be equipped with additional equipment for difficult intubation, including fiberoptic capability. If general anesthesia is required in obese women, an additional nursing staff member will be needed to assist with positioning54 if the anesthesia staff deem this necessary. If adequate resources, including anesthesia staffing, are not available for the safe delivery of a complicated patient, referral to another center may be considered on a case-bycase basis.
Surgical considerations: cesarean incision type, antibiotic dosing, and venous thromboembolism prophylaxis There are no randomized controlled studies to guide management with respect to surgical incision type for cesarean delivery. The majority of studies are retrospective and several are underpowered to detect a difference in wound complications. In several of these studies,55-57 women who had a vertical skin incision tended to have a higher burden of disease or more risk factors for intraoperative or postoperative complications. Based on limited evidence, a transverse skin incision (Pfannensteil or Maylard if necessary) should be used as the first option. However, the decision regarding type of skin incision should be individualized and based on achieving adequate exposure to safely complete the surgical procedure. Supraumbilical incisions remain a limited option but may
Obstetrics increase the rate of classical uterine incision.58 At some centers, it is a common practice to elevate the pannus using medical tape, but this should be done with caution because it can increase intrathoracic pressure and adversely affect ventilation. Collaboration with anesthesia colleagues is recommended. Alternative options include the use of a self-retaining wound retractor, commercially marketed as O retractors. These have been found to aid in providing adequate surgical exposure for most obese women without the risk of affecting ventilation. Additionally, obese women are at increased risk of surgical site infections59; therefore, higher doses of prophylactic antibiotics should be considered with increasing maternal weight.60 Although there are few data to guide dosing, our institution uses cefazolin 2 g intravenously (weight
ajog.org
OBSTETRICS
The multidisciplinary approach to the care of the obese parturient Neda Ghaffari, MD; Sindhu K. Srinivas, MD, MSCE; Celeste P. Durnwald, MD
Maternal obesity in pregnancy is associated with increased maternal and fetal risks. Pregnancy management should include counseling, screening, and optimization of maternal health, increased fetal surveillance, and preparation for parturition. A multidisciplinary approach should be implemented including collaboration from obstetricians, nutritionists, anesthesiologists, social workers, and neonatologists to optimize perinatal outcomes. Pregnancy is an ideal window of opportunity to influence both the patient’s long-term health and the health of the offspring. Key words: adverse pregnancy outcomes, fetal overgrowth, obesity
I
n the United States, the prevalence of obesity is increasing. In 2012, 36.5% of US adult women reported a body mass index (BMI) of 30 kg/m2 or greater, which classified them as obese.1 Furthermore, more than 50% of all pregnant women are overweight or obese.2 Maternal obesity connotes an increased risk of the following perinatal complications: gestational hypertension, preeclampsia, gestational diabetes, cesarean delivery,3 miscarriage,4 anesthesia difficulties,5 failed induction of labor, postpartum hemorrhage, infectious morbidity, and venous thromboembolism.6 Additionally, infants born to obese women are at increased risk of congenital anomalies, prematurity, stillbirth, macrosomia with possible birth injury,
From the Maternal and Child Health Research Program, Department of Obstetrics and Gynecology, Center for Research on Reproduction and Women’s Health, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA. Received Dec. 9, 2014; revised Feb. 20, 2015; accepted March 1, 2015. The authors report no potential conflicts of interest. Corresponding author: Neda Ghaffari, MD. [email protected] 0002-9378/$36.00 Published by Elsevier Inc. http://dx.doi.org/10.1016/j.ajog.2015.03.001
and childhood obesity.7,8 Maternal obesity has long-term health implications for the mother including the development of metabolic and cardiovascular disease.9 The management of obese women can be challenging for clinicians and hospital systems. Obese women require more health care resources and additional equipment to provide the necessary and appropriate prenatal and delivery care. This ultimately leads to increased health care costs.10 Although the focus of this review is to provide guidelines for a multidisciplinary approach to the care of the obese parturient, studies regarding the efficacy of these interventions are limited. A pragmatic approach to comprehensive care of obese women includes specialized nursing care, anesthesia, and obstetrical staff as well as nutritional and social work support. By using an interdisciplinary approach to health care, providers can not only optimize care related to the current pregnancy but also discuss the long-term implications of obesity on a woman’s future health, thereby creating a framework for change.
Classification of obesity The American Congress of Obstetricians and Gynecologists (ACOG) endorses the World Health Organization’s and the National Institutes of Health’s definitions for obesity: underweight as a BMI
318 American Journal of Obstetrics & Gynecology SEPTEMBER 2015
of 18.5 kg/m2, normal weight as a BMI of 18.5e24.9 kg/m2, overweight as a BMI of 25.0e29.9 kg/m2, and obesity as a BMI of 30 kg/m2 or greater. Obesity can be further subdivided into class I (30.0e34.9 kg/m2), class II (35.0e39.9 kg/m2), and class III (>40 kg/m2).11,12 The Institute of Medicine reexamined recommendations for gestational weight gain in pregnancy in 2009 based on more women entering pregnancy at heavier BMIs and gaining excess weight during pregnancy. This increases perinatal risks to both the mother and fetus.13 Current recommendations for weight gain in pregnancy based on prepregnancy BMI are listed in Table 1. A common criticism of the newly adopted guidelines is that weight gain is not stratified by class of obesity. Based on expert opinion and clinical judgment, there is no absolute minimum amount of weight gain necessary as long as fetal growth is assessed and is appropriate for the stated gestational age.
Preconception care In reproductive-aged obese women, optimization of pregnancy outcomes should begin with preconception counseling (Table 2). The optimal time for women to improve their health and decrease weight-related complications is prior to pregnancy. Weight management is an essential part of counseling at the time of annual health maintenance. Achieving a normal BMI prior to pregnancy decreases the rate of perinatal complications more than any other intervention during pregnancy, such as minimizing weight gain. Women can often decrease risks of adverse outcomes in pregnancy with modest weight reductions of as little as 10 pounds.14 Women’s health providers of all disciplines should consider offering community health resources for weight loss consultation with a nutritionist.
Obstetrics
ajog.org Health care coverage should focus on these preventative efforts. Realistic goals for weight loss should be set. Additionally, bariatric surgery prior to conception has been shown to improve perinatal outcomes in obese women.15,16 A subset of obese women would benefit from referral for bariatric surgery.17 In general, bariatric surgery is considered for patients with a BMI greater than 40 kg/m2 or a BMI greater than 35 kg/m2 and at least 1 obesity-related comorbidity, most commonly: type 2 diabetes, hypertension, hyperlipidemia, obstructive sleep apnea (OSA), obesityhypoventilation syndrome, or asthma.18 In many centers, including our own, at least 2 months of medical weight management needs to be completed in the bariatric surgery program, and medical comorbidities must be optimized prior to undergoing the operative procedure. If a patient is planning a future pregnancy, she should delay pregnancy following bariatric surgery for 1-2 years to allow for complete weight loss and recovery.19
Health screening for comorbid conditions Obese women should be screened for medical comorbidities before conception or in early pregnancy. This includes screening for type 2 diabetes mellitus, chronic hypertension, cardiac disease, and obstructive sleep apnea.20 Standard screening methods such as the 2 hour oral glucose tolerance test, hemoglobin A1C, and ambulatory blood pressure assessment should be completed. An electrocardiogram (EKG) may be considered in select cases of medical comorbidities, with echocardiogram if EKG findings are suggestive of an abnormality. The Snoring, Tired, Observed, and blood Pressure (STOP) questionnaire should be used to screen for sleep apnea (Table 3). All women should be screened for dyslipidemia at age 45 years, and testing at age 20-45 years should be considered in women with obesity, especially if other risk factors of coronary heart disease (diabetes, previous personal history of coronary heart disease or noncoronary atherosclerosis, family history
Clinical Opinion
TABLE 1
IOM recommendations for weight gain in pregnancy based on prepregnancy BMI BMI, kg/m2
Total weight gain range, lb
Rates of weight gain second and third trimester, lb/wk (mean range)
Underweight
35 kg/m2), and preeclampsia (OR, 1.6; 95% CI, 1.1e2.25 for BMI 30e34.9 kg/m2; OR, 3.3; 95% CI, 2.4e4.5 for BMI >35 kg/m2)3 as well as intrauterine fetal demise (OR, 4.3; 95% CI, 2.0e9.3).27,28 In early pregnancy, screening with an
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Clinical Opinion
Obstetrics
ajog.org
TABLE 2
Key considerations in the care of obese women in pregnancy Phase of pregnancy care
Considerations
Preconception
Document height, weight, BMI Counsel on risks during pregnancy and for long-term maternal health Screen for diabetes with a 2 hour glucose tolerance test or HbA1C Document blood pressure Consider EKG, especially with comorbidities Consider echocardiogram if EKG abnormalities Screen for depression; refer to mental health professional if indicated Screen for obstructive sleep apnea (Table 3); refer to sleep specialist if indicated Consider lipid screening Discuss weight loss and exercise Refer to nutritionist Consider referral to bariatric surgery program Arrange follow-up to track weight loss and review goals
Prenatal care
Document height, weight, and BMI at every visit Discuss weight gain goals per IOM guidelines (Table 1) and address throughout prenatal care Refer to nutritionist Recommend at least 30 minutes of daily exercise Counsel on risks of obesity in pregnancy Recommend first-trimester ultrasound for dating and diagnosis of multiple gestation Early 1 hour GCT Consider baseline EKG (if not done preconceptionally), especially with comorbidities Screen for obstructive sleep apnea (Table 3); refer to sleep specialist if indicated Offer aneuploidy screening and discuss limitations in obesity Schedule anatomical survey at 20 weeks and discuss limitations in obesity Discuss delivery planning Discuss neuraxial anesthesia and set expectations for difficult placement Growth ultrasound at 32 weeks If BMI >40 kg/m2 or per regional guidelines: consider antepartum testing, starting at 32 weeks
Intrapartum care
Induction of labor by obstetric indications or for comorbidities Anesthesia consult early in labor Early epidural placement Establish reliable fetal monitoring Active management of labor with preparedness for cesarean delivery If delivery via cesarean delivery: 1. Decide on incision type and discuss with patient 2. Consider using self-retaining wound retractor 3. Consider increased dose of preoperative antibiotic (cefazolin 3 g IV [weight 120 kg])
Postpartum
Encourage ambulation Consider postpartum chemoprophylaxis in high-risk patients Contraceptive counseling Encourage breast-feeding Establish a plan for postpartum weight loss
BMI, body mass index; EKG, electrocardiogram; GCT, glucose challenge test; HbA1C, hemoglobin A1C; IOM, Institute of Medicine; IV, intravenous. Ghaffari. Multidisciplinary approach to care of obese parturient. Am J Obstet Gynecol 2015.
early 1-hour glucose challenge test as well as a baseline EKG is recommended. Intrapartum complications include difficulty or inability to accurately monitor the fetus in labor, increased risk of failed induction of labor, and cesarean delivery.3 A delivery plan should be made in the office setting and patient expectations for parturition should be
set. Neuraxial anesthesia in labor should be encouraged, and appropriate expectations should be established regarding the possible difficulty in its placement29 and the increased need for replacement to achieve adequate pain relief.30 Postpartum complications, including postpartum hemorrhage, wound disruption, or infection in the event of
320 American Journal of Obstetrics & Gynecology SEPTEMBER 2015
cesarean delivery, and increased risk of venous thromboembolism (VTE) postpartum12 should be reviewed.
Ultrasound Establishing accurate dating of the pregnancy in the first trimester is important. Obese women may have irregular menses due to oligoovulation,
Obstetrics
ajog.org and a first-trimester ultrasound is often needed to determine an estimated date of delivery. Additionally, obesity has been associated with an increased risk of twin gestations31 and congenital anomalies, especially congenital heart defects (OR, 2.0; 95% CI, 1.2e3.4) and open neural tube defects (OR, 3.5; 95% CI, 1.2e10.3).32 To compound this problem, ultrasound detection of anomalies is more difficult in obese women. Evidence from the First- and Second-Trimester Evaluation of Risk trial suggests that there are a greater number of missed fetal ultrasound diagnoses in obese women.33 Maternal obesity is associated with at least a 20% lower detection of fetal anomalies34 and an increased need for repeat imaging to complete the anatomical survey.35 Women should be offered routine aneuploidy screening and counseled regarding the limitations of ultrasound in detection of anomalies based on their BMI. The overall completion rate of the anatomical survey improves with increasing gestational age and may be best at 20e23 weeks.36 In some centers, including our own, the routine anatomical survey is performed at 20 weeks’ gestation with repeat imaging in 2 weeks if suboptimal views are obtained, which is consistent with expert opinion.35 This approach balances improved detection rates with opportunity for the patient to electively terminate a pregnancy if severe defects are identified.
Fetal growth disturbance and risk of stillbirth Obesity is a risk factor for fetal overgrowth.37-39 Prediction of fetal overgrowth remains difficult40 because fetal growth potential is multifactorial and may be affected by comorbid diabetes and gestational weight gain as well as genetic, racial, and ethnic factors.40 Given the increased risk for growth disturbance and inaccuracy of fundal heights in this population, many providers recommend, at minimum, a single growth ultrasound in the third trimester.41 Additional ultrasound surveillance may be indicated if macrosomia is diagnosed or if there is clinical
Clinical Opinion
TABLE 3
STOP questionnairea S
“Do you snore loudly (louder than talking or loud enough to be heard through closed doors)?”
T
“Do you often feel tired, fatigued, or sleepy during daytime?”
O
“Has anyone observed you stop breathing during your sleep?”
P
“Do you have or are you being treated for high blood pressure?”
a
If answer is yes to 2 or more questions, refer to a sleep specialist. Adapted from Chung et al.44
Ghaffari. Multidisciplinary approach to care of obese parturient. Am J Obstet Gynecol 2015.
concern for fetal overgrowth based on increased fundal height. Obese women are also at increased risk for stillbirth, even after adjusting for both maternal age and comorbid conditions such as hypertension and diabetes.42,43 It is not known whether fetal demise in this group is caused by uteroplacental insufficiency. Although the cost-effectiveness of antenatal testing is yet to be proven, such interventions are often used to potentially offset the stillbirth risk, even in the absence of comorbidities. Although more studies are needed to determine the optimal indications for antenatal testing in this population, one approach that the authors support is to recommend antenatal testing in women with a BMI of greater than 40 kg/m2. The risk of stillbirth must be balanced with the risk of failed induction of labor in this population; therefore, the authors advocate for awaiting spontaneous labor in this group without other medical or obstetrical indications for delivery.
Screening for sleep apnea Obesity is a risk factor for sleepdisordered breathing. Sleep disturbance has been linked to inflammation, oxidative stress, endothelial dysfunction, and metabolic dysregulation in the nonpregnant population. Although the literature on OSA during pregnancy is limited, treatment of OSA has been shown to decrease the rates of gestational diabetes mellitus and hypertensive disorders of pregnancy in small studies. Although no screening tool has been validated in a pregnant population, the Berlin, STOP, and Epworth Sleepiness Scales are the most commonly utilized.
The STOP questionnaire has been validated with polysomnography in nonpregnant populations (Table 3).44 It offers a simple, straightforward approach to screening in a busy clinical practice. In general, when screening with the STOP questionnaire, a woman is considered screen positive if affirmative answers are obtained on 2 or more questions. When screening obese women for sleep-disordered breathing, it is optimal to allow adequate time for a formal evaluation and accurate diagnosis because subsequent treatment with continuous positive airway pressure may decrease adverse perinatal outcomes. It may not be cost effective or pragmatic to screen in the third trimester because delivery might occur prior to a complete work-up. Based on available resources and collaboration with sleep medicine specialists, hospital systems can design screening and evaluation algorithms that incorporate a woman’s BMI, comorbid conditions, and the ability to receive adequate treatment. The relationship between obesity, sleep-disordered breathing, and adverse pregnancy outcomes continues to be an active area of research. A large observational study of 10,000 nulliparous women, the Nulliparous Pregnancy Outcomes Study: Monitoring Mothersto-be study (clinical trials identification NCT01322529), will contribute data on sleep breathing, sleep patterns, and sleep quality in selected nulliparous women.
Delivery considerations Equipment Hospital systems, including outpatient and inpatient facilities, need to be adequately equipped to care for and
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Clinical Opinion
Obstetrics
TABLE 4
Specialized medical equipment for the obese gravida Labor room and hospital room equipment
Labor beds and stretchers rated for morbidly obese patients Long exam gloves Long speculums Large blood pressure cuffs Large sequential compression devises Patient lifts Bariatric wheelchairs Seats for waiting room and hospital rooms Consider alternative fetal heart rate monitoring equipment
Operating room equipment
Operating room tables rated for morbidly obese patients Patient lifts Long instrument tray for cesarean section Consider self-retaining retractors
Anesthesia equipment
Long spinal needles and IV cannulas Wedge for patient positioning for intubation Fiberoptic bronchoscope
IV, intravenous. Ghaffari. Multidisciplinary approach to care of obese parturient. Am J Obstet Gynecol 2015.
evaluate obese pregnant women. Labor and delivery units should stock durable medical equipment that will allow for accurate basic obstetric assessments. This includes long examination gloves, long speculums, large blood pressure cuffs, large sequential compression devices, and specialized surgical equipment (Table 4). Patient lifts are often needed in labor and delivery and postpartum units to safely and efficiently transport patients and decrease the rate of work-related injury.45 Table extenders should be available for the operating room table. Bariatric wheelchairs and appropriately sized seats in hospital waiting rooms are recommended. Hospital systems who care for a large proportion of obese women, including our own, have adopted the use of a monitor that utilizes maternal abdominal fetal electrocardiogram signals46 rather than Doppler ultrasound for obese patients, given that intrapartum fetal monitoring can have poor signal quality in obese women.12 Communication The key for safe obstetrical care of medically complicated patients is effective communication among the multidisciplinary team. Appropriate hand-offs and a culture of safety are an integral part of
caring for all pregnant patients, especially in the care of the obese parturient. Direct communication among the nursing staff, obstetricians, and anesthesiologists is recommended from the time of admission, throughout the labor course, and during the postpartum period. It is crucial to discuss maternal BMI during all patient hand-offs and on multidisciplinary rounds. It is helpful to clearly document BMI on hospital admission and nursing assessment forms and the labor and delivery board as well as in the electronic medical record. Many centers use an early anesthesia consult shortly after admission for laboring obese women. Delivery Women who are obese are thought to have slower labor curves than women of normal weight.47,48 Given the challenges with labor induction and augmentation in this population, induction of labor for obesity in isolation is not recommended. However, these women often have other comorbid medical conditions that necessitate labor induction. In cases of abnormal fetal heart tracings, providers must keep in mind that there will be delays in transporting the patient, positioning in the operating room, and obtaining adequate anesthesia.
322 American Journal of Obstetrics & Gynecology SEPTEMBER 2015
ajog.org An approach of active labor management and preparedness for cesarean delivery is recommended; the threshold to call a cesarean delivery for a category II electronic fetal heart rate tracing may be lower in obese patients, given the concern for logistical delays. In the setting of a category III electronic fetal monitoring tracing, a cesarean delivery should be accomplished as expeditiously as feasible.49 If a decision is made to proceed with a cesarean delivery based on maternal or fetal indications, the maternal BMI should be communicated with nursing, anesthesia, and obstetrics providers. An interdisciplinary team discussion should occur once a cesarean delivery is called to communicate salient aspects of the patient’s course, including her BMI. An additional nurse may be needed to help prepare the patient in the operating room or set up the lift and extenders. Anesthetic considerations Obese parturients are at increased risk of anesthesia-related complications such as failed intubation, aspiration, and nonfunctional epidural anesthesia.50 In one study, the initial epidural catheter failed in 42% of obese (obesity class III) patients (compared with 6% in controls; P < .0001), and intubation was characterized as difficult in 6 of 17 obese patients (0 of 8 controls; P ¼ .059).51 Obese patients should be evaluated by an anesthesiologist shortly after admission.52 Airway evaluation should be completed including Mallampati score; mouth opening and neck range of motion and patients with difficult airways should be identified.53 If a patient is expected to be at high risk for anesthetic complications, this should be considered in delivery planning. Depending on institutional resources, it may be reasonable for women deemed to be of significant anesthetic risk or medical comorbidities to undergo cesarean delivery in the main operating rooms in which specialized equipment and staff are available. This should be planned with the multidisciplinary team prior to the patient’s admission to labor and delivery. Obese women are at an increased risk of requiring general
ajog.org anesthesia.6 Therefore, the use of epidural anesthesia should be encouraged and placed early in the labor course should there be a need for cesarean delivery, thus avoiding general anesthesia. During the informed consent process, the patient should be counseled that epidural placement may be difficult29 and there is an increased need for replacement to achieve adequate pain relief.30 It is recommended that anesthesia assessments occur frequently in morbidly obese patients. The functionality and adequacy of regional anesthesia should be checked regularly with a low threshold to replace poorly functioning epidurals. Operating rooms should be equipped with additional equipment for difficult intubation, including fiberoptic capability. If general anesthesia is required in obese women, an additional nursing staff member will be needed to assist with positioning54 if the anesthesia staff deem this necessary. If adequate resources, including anesthesia staffing, are not available for the safe delivery of a complicated patient, referral to another center may be considered on a case-bycase basis.
Surgical considerations: cesarean incision type, antibiotic dosing, and venous thromboembolism prophylaxis There are no randomized controlled studies to guide management with respect to surgical incision type for cesarean delivery. The majority of studies are retrospective and several are underpowered to detect a difference in wound complications. In several of these studies,55-57 women who had a vertical skin incision tended to have a higher burden of disease or more risk factors for intraoperative or postoperative complications. Based on limited evidence, a transverse skin incision (Pfannensteil or Maylard if necessary) should be used as the first option. However, the decision regarding type of skin incision should be individualized and based on achieving adequate exposure to safely complete the surgical procedure. Supraumbilical incisions remain a limited option but may
Obstetrics increase the rate of classical uterine incision.58 At some centers, it is a common practice to elevate the pannus using medical tape, but this should be done with caution because it can increase intrathoracic pressure and adversely affect ventilation. Collaboration with anesthesia colleagues is recommended. Alternative options include the use of a self-retaining wound retractor, commercially marketed as O retractors. These have been found to aid in providing adequate surgical exposure for most obese women without the risk of affecting ventilation. Additionally, obese women are at increased risk of surgical site infections59; therefore, higher doses of prophylactic antibiotics should be considered with increasing maternal weight.60 Although there are few data to guide dosing, our institution uses cefazolin 2 g intravenously (weight
