DOI 10.1515/jpm-2013-0146 J. Perinat. Med. 2014; 42(3): 385–391
Cristina Plevani*, Anna Locatelli, Giuseppe Paterlini, Alessandro Ghidini, Paolo Tagliabue, John C. Pezzullo and Patrizia Vergani
Fetal hydronephrosis: natural history and risk factors for postnatal surgery Abstract Background: The objective of this study was to assess the ability of prenatal ultrasound to predict an unfavorable outcome and the need for postnatal surgery in cases of fetal hydronephrosis (HY). Methods: Antenatal HY was classified according to the renal pelvis anteroposterior (AP) diameter in the third trimester. Postnatal outcome was considered favorable in the pre sence of spontaneous resolution or postnatal diagnosis of HY 20 mm HY or urinary tract pathologies. Results: Prenatal diagnosis of HY was made in 120 fetuses (for a total of 161 abnormal renal units). The rates of postnatal urinary tract pathology were 14, 27 and 53% for antenatal HY of ≤ 7, 8–15 and > 15 mm, respectively. An AP diameter ≥ 7 mm in the third trimester had a sensitivity of 100% and a specific ity of 23% to predict unfavorable outcome. A formula inclu sive of AP diameter and presence or absence of urinary tract anomalies can predict the need for postnatal surgery. Conclusions: The majority of infants with congenital HY have a favorable postnatal outcome. Risk of unfavorable outcome increases with the degree of dilatation of the renal pelvis and the presence of urinary tract anomalies. An AP diameter ≥ 7 mm in the third trimester warrants postnatal follow-up. Keywords: Antenatal hydronephrosis; postnatal outcome; postnatal renal function; postnatal surgery; prenatal diagnosis; urinary tract. *Corresponding author: Cristina Plevani, MD, Department of Obstetrics and Gynecology, San Gerardo Hospital, University of Milano-Bicocca, Via Pergolesi 33, 20052, Monza (MI), Italy, Tel.: +39 039 233 3110, E-mail: [email protected] Anna Locatelli: Departments of Obstetrics and Gynecology, Vimercate and Desio Hospital, Carate Brianza, University of Milano-Bicocca, Italy Giuseppe Paterlini and Paolo Tagliabue: Department of Neonatology, San Gerardo Hospital, University of Milano-Bicocca, Monza, Italy Alessandro Ghidini: Perinatal Diagnostic Center, Inova Alexandria Hospital, Alexandria, VA, USA John C. Pezzullo: Departments of Pharmacology and Biostatistics, Georgetown University, Washington, DC, USA Patrizia Vergani: Department of Obstetrics and Gynecology, San Gerardo Hospital, University of Milano-Bicocca, Monza, Italy
Introduction Congenital hydronephrosis (HY) is the most common fetal malformation, and it is diagnosed in the presence of an abnormal dilatation of renal pelvis and/or calyces, with or without changes in renal parenchyma [19]. It occurs in 1–4% of pregnancies [4, 11]; it is more common in male fetuses and more frequently unilateral in location. Urinary tract obstruction, typically at the ureteropelvic junction, and vesicoureteral reflux are the most common causes of HY, whereas hydroureteronephrosis and duplex renal system are less common causes of HY. During pregnancy, diagnosis of HY is made by docu mentation of increased anteroposterior (AP) diameter of the renal pelvis. Dilatation can progress, regress or remain stable during gestation. At birth, about 35% of neonates with prenatal diagnosis of HY show a normal anatomy at ultrasound examination [13, 18]. Neonatal outcome depends on the severity of the renal pelvic dilation as well as on the type and degree of associated anomalies and causative factors. A worse prognosis is predicted by early prenatal diagnosis, marked bilateral dilatation, persistent bladder obstruction, oligohydramnios and secondary pul monary hypoplasia [7]. The purposes of this study were to evaluate the ante natal and postnatal evolution of congenital HY and to assess the ability of prenatal ultrasound to predict an unfavorable postnatal outcome and the need for postna tal surgery.
Methods We conducted a retrospective cohort study of all fetuses with prena tal ultrasonographic diagnosis of HY from January 2002 to December 2007 and delivered at San Gerardo Hospital, University of MilanoBicocca, Monza, Italy. The study protocol was approved by the insti tution’s ethics committee, and it did not require informed consent. In Italy, all women are offered routine ultrasound in the early second trimester to screen for structural fetal anomalies and in the third tri mester to evaluate fetal growth. We included both cases diagnosed at our prenatal diagnostic center and those referred from other cent ers. Excluded were cases of HY associated with extra-urinary tract
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386 Plevani et al., Fetal hydronephrosis: natural history and risk factors for postnatal surgery anomalies or renal parenchyma anomalies. Diagnosis of HY was made in the presence of an AP diameter of the renal pelvis > 5 mm during the third trimester of pregnancy. Antenatal HY was classified into first degree (dilatation of 5–7 mm), second degree (8–15 mm) and third degree ( > 15 mm). At the prenatal ultrasound scan, we defined hydroureteronephrosis as a dilatation of both the renal pelvis and the ureter. A ureteropelvic junction obstruction (UPJO) was suspected in the presence of moderate or severe renal pelvic dilatation, without ureteral or bladder dilatation. Cases of hydroureteronephrosis or HY with variable degrees of severity during the scan or at serial scans were considered highly suggestive of vesicoureteral reflux (VUR). Duplex renal system was diagnosed in the presence of at least two of these conditions: asymmetric renal sizes, dilatation of the upper pole collecting system, reflux that intermittently dilated the lower pole, severe ureteropelvic junction obstruction, ureteral dilatation and ureterocele. Posterior urethral valves (PUVs) were suspected in the presence of variable HY (typically bilateral), renal cystic dysplasia, dilated thick-walled bladder, distension of the proximal urethra and decreased amniotic fluid in male fetuses. In the presence of a diagnosis of HY, fetal anatomy was carefully evaluated to detect other abnormalities or markers of aneuploidy. If an associated urinary tract anomaly was diagnosed, consultation was arranged with a neonatologist and a pediatric urologist. Serial ultrasound exams were performed by obstetricians with expertise in prenatal ultrasound diagnosis every 2–4 weeks depending on the relevance of the anomaly. Need for antenatal therapy and option of termination of pregnancy were discussed depending on the severity of the condition. After delivery, cases were referred for neonatal fol low-up if the AP diameter of the renal pelvis at the last sonographic exam was > 5 mm. Postnatal ultrasound examinations were performed at 1 week and at 1, 3 and 6 months, with more frequent evaluations and addi tional imaging studies (e.g., radionuclide cystography, MAG3 diuretic renogram, voiding cystourethrogram and urography) if indicated (Figure 1). Antibiotic prophylaxis was administered to all infants with vesicoureteral reflux or significant hydroureteronephrosis. Postnatal
HY was classified according to the renal pelvis AP diameter into first degree (diameter ≤ 10 mm), second degree (11–20 mm) and third degree ( > 20 mm). A pediatric urologist was involved in the counseling of complex cases and reviewed prenatal scans; need, timing and modalities of a postnatal surgical treatment were decided at the end of the diagnos tic work-up. When available, standardized criteria and practices for surgical intervention were followed [12, 24]. We performed two statistical analyses. In the first one, we evalu ated which antenatal factors have relevance for postnatal urologic outcome. We classified as favorable outcome cases that resolved spontaneously in utero or during the neonatal period, as well as those with postnatal diagnosis of first- or second-degree HY. Unfavorable outcome was defined as postnatal diagnosis of third-degree HY, ureteropelvic junction obstruction, megaureter, vesicoureteral reflux, hydroureteronephrosis, duplex renal system, horseshoe kid ney, posterior urethral obstruction or need for surgery. In the second analysis, we assessed which antenatal variables (i.e., renal pelvis AP diameter or the presence of other urinary tract anomalies associated with HY) predict postnatal urinary tract pathology (as a cause of HY) or need for postnatal surgery. Statistical analysis included one-way analysis of variance test for comparison of continuous variables and the χ2-test for dichotomous variables, with a P
Cristina Plevani*, Anna Locatelli, Giuseppe Paterlini, Alessandro Ghidini, Paolo Tagliabue, John C. Pezzullo and Patrizia Vergani
Fetal hydronephrosis: natural history and risk factors for postnatal surgery Abstract Background: The objective of this study was to assess the ability of prenatal ultrasound to predict an unfavorable outcome and the need for postnatal surgery in cases of fetal hydronephrosis (HY). Methods: Antenatal HY was classified according to the renal pelvis anteroposterior (AP) diameter in the third trimester. Postnatal outcome was considered favorable in the pre sence of spontaneous resolution or postnatal diagnosis of HY 20 mm HY or urinary tract pathologies. Results: Prenatal diagnosis of HY was made in 120 fetuses (for a total of 161 abnormal renal units). The rates of postnatal urinary tract pathology were 14, 27 and 53% for antenatal HY of ≤ 7, 8–15 and > 15 mm, respectively. An AP diameter ≥ 7 mm in the third trimester had a sensitivity of 100% and a specific ity of 23% to predict unfavorable outcome. A formula inclu sive of AP diameter and presence or absence of urinary tract anomalies can predict the need for postnatal surgery. Conclusions: The majority of infants with congenital HY have a favorable postnatal outcome. Risk of unfavorable outcome increases with the degree of dilatation of the renal pelvis and the presence of urinary tract anomalies. An AP diameter ≥ 7 mm in the third trimester warrants postnatal follow-up. Keywords: Antenatal hydronephrosis; postnatal outcome; postnatal renal function; postnatal surgery; prenatal diagnosis; urinary tract. *Corresponding author: Cristina Plevani, MD, Department of Obstetrics and Gynecology, San Gerardo Hospital, University of Milano-Bicocca, Via Pergolesi 33, 20052, Monza (MI), Italy, Tel.: +39 039 233 3110, E-mail: [email protected] Anna Locatelli: Departments of Obstetrics and Gynecology, Vimercate and Desio Hospital, Carate Brianza, University of Milano-Bicocca, Italy Giuseppe Paterlini and Paolo Tagliabue: Department of Neonatology, San Gerardo Hospital, University of Milano-Bicocca, Monza, Italy Alessandro Ghidini: Perinatal Diagnostic Center, Inova Alexandria Hospital, Alexandria, VA, USA John C. Pezzullo: Departments of Pharmacology and Biostatistics, Georgetown University, Washington, DC, USA Patrizia Vergani: Department of Obstetrics and Gynecology, San Gerardo Hospital, University of Milano-Bicocca, Monza, Italy
Introduction Congenital hydronephrosis (HY) is the most common fetal malformation, and it is diagnosed in the presence of an abnormal dilatation of renal pelvis and/or calyces, with or without changes in renal parenchyma [19]. It occurs in 1–4% of pregnancies [4, 11]; it is more common in male fetuses and more frequently unilateral in location. Urinary tract obstruction, typically at the ureteropelvic junction, and vesicoureteral reflux are the most common causes of HY, whereas hydroureteronephrosis and duplex renal system are less common causes of HY. During pregnancy, diagnosis of HY is made by docu mentation of increased anteroposterior (AP) diameter of the renal pelvis. Dilatation can progress, regress or remain stable during gestation. At birth, about 35% of neonates with prenatal diagnosis of HY show a normal anatomy at ultrasound examination [13, 18]. Neonatal outcome depends on the severity of the renal pelvic dilation as well as on the type and degree of associated anomalies and causative factors. A worse prognosis is predicted by early prenatal diagnosis, marked bilateral dilatation, persistent bladder obstruction, oligohydramnios and secondary pul monary hypoplasia [7]. The purposes of this study were to evaluate the ante natal and postnatal evolution of congenital HY and to assess the ability of prenatal ultrasound to predict an unfavorable postnatal outcome and the need for postna tal surgery.
Methods We conducted a retrospective cohort study of all fetuses with prena tal ultrasonographic diagnosis of HY from January 2002 to December 2007 and delivered at San Gerardo Hospital, University of MilanoBicocca, Monza, Italy. The study protocol was approved by the insti tution’s ethics committee, and it did not require informed consent. In Italy, all women are offered routine ultrasound in the early second trimester to screen for structural fetal anomalies and in the third tri mester to evaluate fetal growth. We included both cases diagnosed at our prenatal diagnostic center and those referred from other cent ers. Excluded were cases of HY associated with extra-urinary tract
Brought to you by | University of California Authenticated Download Date | 6/3/15 10:28 PM
386 Plevani et al., Fetal hydronephrosis: natural history and risk factors for postnatal surgery anomalies or renal parenchyma anomalies. Diagnosis of HY was made in the presence of an AP diameter of the renal pelvis > 5 mm during the third trimester of pregnancy. Antenatal HY was classified into first degree (dilatation of 5–7 mm), second degree (8–15 mm) and third degree ( > 15 mm). At the prenatal ultrasound scan, we defined hydroureteronephrosis as a dilatation of both the renal pelvis and the ureter. A ureteropelvic junction obstruction (UPJO) was suspected in the presence of moderate or severe renal pelvic dilatation, without ureteral or bladder dilatation. Cases of hydroureteronephrosis or HY with variable degrees of severity during the scan or at serial scans were considered highly suggestive of vesicoureteral reflux (VUR). Duplex renal system was diagnosed in the presence of at least two of these conditions: asymmetric renal sizes, dilatation of the upper pole collecting system, reflux that intermittently dilated the lower pole, severe ureteropelvic junction obstruction, ureteral dilatation and ureterocele. Posterior urethral valves (PUVs) were suspected in the presence of variable HY (typically bilateral), renal cystic dysplasia, dilated thick-walled bladder, distension of the proximal urethra and decreased amniotic fluid in male fetuses. In the presence of a diagnosis of HY, fetal anatomy was carefully evaluated to detect other abnormalities or markers of aneuploidy. If an associated urinary tract anomaly was diagnosed, consultation was arranged with a neonatologist and a pediatric urologist. Serial ultrasound exams were performed by obstetricians with expertise in prenatal ultrasound diagnosis every 2–4 weeks depending on the relevance of the anomaly. Need for antenatal therapy and option of termination of pregnancy were discussed depending on the severity of the condition. After delivery, cases were referred for neonatal fol low-up if the AP diameter of the renal pelvis at the last sonographic exam was > 5 mm. Postnatal ultrasound examinations were performed at 1 week and at 1, 3 and 6 months, with more frequent evaluations and addi tional imaging studies (e.g., radionuclide cystography, MAG3 diuretic renogram, voiding cystourethrogram and urography) if indicated (Figure 1). Antibiotic prophylaxis was administered to all infants with vesicoureteral reflux or significant hydroureteronephrosis. Postnatal
HY was classified according to the renal pelvis AP diameter into first degree (diameter ≤ 10 mm), second degree (11–20 mm) and third degree ( > 20 mm). A pediatric urologist was involved in the counseling of complex cases and reviewed prenatal scans; need, timing and modalities of a postnatal surgical treatment were decided at the end of the diagnos tic work-up. When available, standardized criteria and practices for surgical intervention were followed [12, 24]. We performed two statistical analyses. In the first one, we evalu ated which antenatal factors have relevance for postnatal urologic outcome. We classified as favorable outcome cases that resolved spontaneously in utero or during the neonatal period, as well as those with postnatal diagnosis of first- or second-degree HY. Unfavorable outcome was defined as postnatal diagnosis of third-degree HY, ureteropelvic junction obstruction, megaureter, vesicoureteral reflux, hydroureteronephrosis, duplex renal system, horseshoe kid ney, posterior urethral obstruction or need for surgery. In the second analysis, we assessed which antenatal variables (i.e., renal pelvis AP diameter or the presence of other urinary tract anomalies associated with HY) predict postnatal urinary tract pathology (as a cause of HY) or need for postnatal surgery. Statistical analysis included one-way analysis of variance test for comparison of continuous variables and the χ2-test for dichotomous variables, with a P
