Case Reports
Successful In Utero Intervention for Bilateral Renal Agenesis Jessica L. Bienstock, MD, MPH, Meredith L. Birsner, MD, Fred Coleman, MD, and Nancy A. Hueppchen, MD, MSc BACKGROUND: We report a case of bilateral renal agenesis treated with serial amnioinfusion in which the newborn survived the newborn period and was able to undergo peritoneal dialysis as a bridge to planned renal transplantation. CASE: A 34-year-old woman, gravida 1 para 0, presented at 23 1/7 weeks of gestation with a diagnosis of anhydramnios and bilateral renal agenesis. The patient underwent weekly serial amnioinfusion with the goal of improving fetal pulmonary development. At 28 weeks of gestation, the patient delivered a live newborn who required minimal respiratory support. The neonate is currently 9 months old and is undergoing daily peritoneal dialysis. CONCLUSION: Serial amnioinfusion appears to have mitigated the severe pulmonary compromise that has, in the past, led to the death of newborns with bilateral renal agenesis. (Obstet Gynecol 2014;124:413–5) DOI: 10.1097/AOG.0000000000000339
B
ilateral renal agenesis is a severe fetal anomaly occurring in 1 in 3,000 pregnancies.1 Previously considered uniformly fatal, affected fetuses die in utero from cord compression, or newborns die within hours of birth because of severe pulmonary hypoplasia. Case reports of monoamniotic twins who were discordant for bilateral renal agenesis have described See related editorial on page 411.
From the Johns Hopkins University School of Medicine, Baltimore, Maryland, and Legacy Maternal Fetal Medicine, Vancouver, Washington. Corresponding author: Jessica L. Bienstock, MD, MPH, Johns Hopkins University School of Medicine, 600 North Wolfe St., Baltimore, MD 21287; e-mail: [email protected]. Financial Disclosure The authors did not report any potential conflicts of interest. © 2014 by The American College of Obstetricians and Gynecologists. Published by Lippincott Williams & Wilkins. ISSN: 0029-7844/14
VOL. 124, NO. 2, PART 2, AUGUST 2014
normal pulmonary outcomes for the bilateral renal agenesis twin. However, all but one of these newborns have died as a result of renal failure within 12 days of life.2–4 One newborn was administered peritoneal dialysis but died at 2 months of age because of complications of the peritoneal dialysis.5 To date, there have been no long-term survivors of bilateral renal agenesis. Antenatal oligohydramnios, although not anhydramnios, of renal origin has been reported to have survival rates up to 70%, with 75% having normal cognitive and motor development.6
CASE Our patient is a 34-year-old woman, gravida 1 para 0, who presented to our hospital at 23 1/7 weeks of gestation for a second opinion. She specifically requested to discuss the possibility of serial amnioinfusion to prevent pulmonary hypoplasia. She had an uncomplicated antepartum course until diagnosis of bilateral fetal renal agenesis and anhydramnios at 20 weeks of gestation. There were no ultrasound examinations performed between the first trimester and the 20week scan, so the exact point at which anhydramnios occurred is unknown, although we surmise that this occurred early in the second trimester, when fetal urine production usually would be expected to account for the majority of amniotic fluid. Her medical history and family history were unremarkable. Obstetric ultrasonography revealed complete anhydramnios. Other abnormal ultrasonographic findings included bilateral renal agenesis, a narrow-appearing chest with ratio of thoracic circumference to abdominal circumference of 0.7 (normal5more than 0.8), ratio of heart circumference to chest circumference of 0.64 (normal5less than 0.6), dolichocephaly, bilateral clubbed feet, and no visible bladder or stomach. Fetal biometry was equivalent to 22 1/7 weeks of gestation, and the estimated fetal weight was 556 g. The patient was counseled that these findings were most consistent with bilateral renal agenesis and likely would result in Potter sequence and neonatal death from pulmonary hypoplasia. The patient was offered maternal blood testing for circulating cell-free fetal DNA but declined this testing. Based on our experience with performing amnioinfusions for patients with early-onset severe oligohydramnios, we discussed the possibility of serial amnioinfusion with the goal of preventing pulmonary hypoplasia. The patient met with a neonatologist to discuss issues related to prematurity and newborn respiratory distress, as well as a pediatric nephrologist to discuss the possibility of neonatal peritoneal dialysis as a bridge to eventual renal transplantation. Understanding the lack of clear evidence of a successful long-term outcome, the patient chose to undergo serial amnioinfusion. The first infusion was performed at 24 1/7 weeks of gestation. Under ultrasonographic guidance,
OBSTETRICS & GYNECOLOGY
413
a 20-gauge, 15-cm echotip needle was introduced into the amniotic cavity and 250 mL room temperature saline was infused to obtain a normal-appearing amniotic fluid volume (maximum vertical pocket of 3.9 cm). At the conclusion of the procedure, 10 mL indigo carmine was instilled into the amniotic cavity. After insertion of a vaginal tampon and ambulation, the tampon was removed and no blue dye was seen on the tampon, thus confirming that she did not have preterm premature rupture of membranes. The initial amnioinfusion allowed for improved visualization of the fetal anatomy. A normal fetal echocardiogram was obtained. Repeat ultrasound assessment 5 days later revealed a maximum vertical amniotic fluid pocket of 4.4 cm. Of note, the fetal stomach was visualized, and fetal breathing was seen as well. The fetal skull no longer appeared dolichocephalic, the thoracic-to-abdominal ratio was 0.8, and the ratio of heart circumference to chest circumference was 0.6. The feet still appeared clubbed, and no fetal bladder was visualized. The fetus had spontaneously turned from breech to vertex presentation. Over the subsequent 4 weeks, four additional weekly amnioinfusions were performed. The volume of saline infused was based on a goal of obtaining an amniotic fluid index of approximately 10 cm at the conclusion of each infusion. This calculated to approximately 15 mL per week of gestational age. At 28 1/7 weeks of gestation, the patient presented to her local hospital with preterm contractions. Betamethasone was administered to enhance fetal lung maturity. Contractions abated with subcutaneous terbutaline, and she was discharged home. At 28 4/7 weeks of gestation, preterm contractions developed again and she was admitted to the hospital. Magnesium sulfate was begun for fetal neuroprotection, and she was transferred to a hospital with a level 3 neonatal intensive care unit. One day later, after experiencing increasing contractions and pelvic pressure, spontaneous rupture of membranes occurred and soon thereafter she had a spontaneous vaginal delivery of a live female newborn with Apgar scores of 7 at 1 minute and 8 at 5 minutes. The newborn weighed 1,230 g and cried spontaneously at birth. A 10% placental abruption was noted. The newborn had excellent respiratory effort and required only nasal continuous positive airway pressure support. The newborn did not require surfactant administration or intubation. Neonatal examination was remarkable only for the absence of palpable kidneys. The newborn’s admission complete blood count revealed a white blood cell count of 9.3 with 14 bands, and she was treated empirically with intravenous gentamycin and ampicillin. Chest radiograph soon after birth revealed bilateral diffuse interstitial pulmonary infiltrates consistent with respiratory distress syndrome, but appropriate lung volumes. Ultrasonogram confirmed the prenatal diagnosis of bilateral renal agenesis, with no renal tissue identified in the renal fossae nor in any ectopic region of the pelvis. No urinary bladder could be
414
Bienstock et al
In Utero Therapy for Renal Agenesis
identified. Additionally, there was no stigmata of Potter sequence in the newborn. Because of limitations in the services available at the hospital of birth, the newborn was transferred to a major university hospital and began peritoneal dialysis at 36 hours of life. The newborn’s whole-genome array comparative genomic hybridization results were normal. The infant was discharged home at 19 weeks of age with daily home peritoneal dialysis. She required re-hospitalization 3 weeks later due to an obstruction of her peritoneal dialysis catheter that was complicated by the development of peritonitis. She was discharged home after replacement of the catheter and an additional 10-week stay. At the time of writing this article, the newborn is 9 months old and receiving daily home peritoneal dialysis, meeting her gestational age–adjusted milestones, and growing appropriately. The plan is to evaluate her for renal transplantation at 12 to 24 months of age. Written consent was obtained from the patient to allow for publication of this report.
COMMENT The etiology of lung hypoplasia associated with bilateral renal agenesis remains uncertain. The most likely explanation is that fetuses with bilateral renal agenesis lack fluid to draw into their lungs, allowing for the necessary canalicularization at 17 to 26 weeks of gestation,7 and have thoracic compression by the uterine walls because of anhydramnios. Studies of serial amnioinfusion with severe oligohydramnios attributable to preterm premature rupture of membranes have been promising regarding prevention of pulmonary hypoplasia.8–10 In a recent meta-analysis, Porat et al11 found an odds ratio of 0.17 (95% confidence interval 0.04–0.78) for development of pulmonary hypoplasia in patients enrolled in two observational studies and treated with amnioinfusion. However, that same meta-analysis found a nonsignificant odds ratio of 0.30 (95% confidence interval 0.05–1.7) for prevention of pulmonary hypoplasia in patients enrolled in three randomized controlled trials.11 Even if intrauterine death from cord compression and neonatal pulmonary hypoplasia can be prevented, dialysis as a bridge to renal transplantation is the only option if the newborn with bilateral renal agenesis is to survive. Peritoneal dialysis for newborns and infants recently has become a reality, with several case series estimating short-term survival (1–5 years) to range from 52 to 89%.12–14 Although peritoneal dialysis remains challenging in newborns, this technology is rapidly evolving and holds promise as a bridge to eventual renal transplantation. Among a Canadian cohort of
OBSTETRICS & GYNECOLOGY
children initiating renal replacement therapy before age 2 years, 65.5% underwent renal transplantation at a median age of 2.7 years; 26.4% died and 95.7% of these deaths occurred in patients who had not undergone transplantation. Mortality was highest when renal replacement was started before 3 months of age. Other issues in the pediatric renal transplant population include poor growth and immunosuppressant-related infections.12 Shortterm outcomes in prenatally diagnosed obstructive uropathy include a survival rate of 61% when fetuses are shunted in utero. Complications of shunting for obstructive uropathy include preterm delivery, chorioamnionitis, and intrauterine fetal demise.15 This is a novel report of short-term survival for an newborn with bilateral renal agenesis and anhydramnios. After serial amnioinfusion and spontaneous preterm delivery, the newborn displayed gestational age–appropriate lung function. Although prevention of pulmonary hypoplasia by serial amnioinfusion in no way cured the significant challenges of this newborn, it allowed her to become a candidate for neonatal peritoneal dialysis with the ultimate goal of undergoing renal transplantation. We acknowledge that the multiple invasive procedures to which the mother and, later, the newborn were subjected are painful, psychologically traumatic, and costly, and by no means provide guaranteed long-term normal outcomes. This case suggests that serial amnioinfusion may be discussed with patients as one option in the continuum of choices parents of fetuses with severe oligohydramnios attributable to fetal bilateral renal agenesis have to consider. REFERENCES 1. Woodward PJ, Kennedy A, Sohaey R, Byrne JLB, Oh KY, Puchalski MD. Diagnostic imaging—obstetrics. Salt Lake City (UT): Amirsys; 2011:2–28. 2. Klinger G, Merlob P, Aloni D, Maayan A, Sirota L. Normal pulmonary function in a monoamniotic twin discordant for bilateral renal agenesis: report and review. Am J Med Genet 1997;73:76–9.
VOL. 124, NO. 2, PART 2, AUGUST 2014
3. Cilento BG Jr, Benacerraf BR, Mandell J. Prenatal and postnatal findings in monochorionic, monoamniotic twins discordant for bilateral renal agenesis-dysgenesis (perinatal lethal renal disease). J Urol 1994;151:1034–5. 4. Mauer SM, Dobrin RS, Vernier RL. Unilateral and bilateral renal agenesis in monoamniotic twins. J Pediatr 1974;84: 236–8. 5. Perez-Brayfield MR, Kirsch AJ, Smith EA. Monoamniotic twin discordant for bilateral renal agenesis with normal pulmonary function. Urology 2004;64:589. 6. Klaassen I, Neuhaus TJ, Mueller-Wiefel DE, Kemper MJ. Antenatal oligohydramnios of renal origin: long-term outcome. Nephrol Dial Transplant 2007;22:432–9. 7. Kilbride HW, Yeast J, Thibeault DW. Defining limits of survival: lethal pulmonary hypoplasia after midtrimester premature rupture of membranes. Am J Obstet Gynecol 1996;175:675–81. 8. Ogunyemi D, Thompson W. A case controlled study of serial transabdominal amnioinfusions in the management of second trimester oligohydramnios due to premature rupture of membranes. Eur J Obstet Gynecol Reprod Biol 2002;102:167–72. 9. Garzetti GG, Ciavattini A, De Cristofaro F, La Marca N, Arduini D. Prophylactic transabdominal amnioinfusion in oligohydramnios for preterm premature rupture of membranes: increase of amniotic fluid index during latency period. Gynecol Obstet Invest 1997;44:249–54. 10. Tranquilli AL, Giannubilo SR, Bezzeccheri V, Scagnoli C. Transabdominal amnioinfusion in preterm premature rupture of membranes: a randomised controlled trial. BJOG 2005;112:759–63. 11. Porat S, Amsalem H, Shah PS, Murphy KE. Transabdominal amnioinfusion for preterm premature rupture of membranes: a systematic review and metaanalysis of randomized and observational studies. Am J Obstet Gynecol 2012;207:393.e1–e11. 12. Alexander R, Foster B, Tonelli M, Soo A, Nettell-Acquirre A, Hemmelgarn BR, et al. Survival and transplantation outcomes of children less than 2 years of age with end-stage renal disease. Pediatr Nephrol 2012;27:1975–83. 13. Genc G, Bicakci U, Gunaydin M, Tander B, Aygun C, Ozgaya O, et al. Temporary peritoneal dialysis in newborns and children: a single-center experience over five years. Ren Fail 2012;34:1058–61. 14. Vidal E, Edefonti A, Murer L, Gianoglio B, Maringhini S, Pecoraro C, et al. Peritoneal dialysis in infants: the experience of the Italian Registry of Paediatric Chronic Dialysis. Nephrol Dial Transplant 2012;27:388–95. 15. Freedman AL, Johnson MP, Gonzalez R. Fetal therapy for obstructive uropathy: past, present.future? Pediatr Nephrol 2000;14:167–76.
Bienstock et al
In Utero Therapy for Renal Agenesis
415
Successful In Utero Intervention for Bilateral Renal Agenesis Jessica L. Bienstock, MD, MPH, Meredith L. Birsner, MD, Fred Coleman, MD, and Nancy A. Hueppchen, MD, MSc BACKGROUND: We report a case of bilateral renal agenesis treated with serial amnioinfusion in which the newborn survived the newborn period and was able to undergo peritoneal dialysis as a bridge to planned renal transplantation. CASE: A 34-year-old woman, gravida 1 para 0, presented at 23 1/7 weeks of gestation with a diagnosis of anhydramnios and bilateral renal agenesis. The patient underwent weekly serial amnioinfusion with the goal of improving fetal pulmonary development. At 28 weeks of gestation, the patient delivered a live newborn who required minimal respiratory support. The neonate is currently 9 months old and is undergoing daily peritoneal dialysis. CONCLUSION: Serial amnioinfusion appears to have mitigated the severe pulmonary compromise that has, in the past, led to the death of newborns with bilateral renal agenesis. (Obstet Gynecol 2014;124:413–5) DOI: 10.1097/AOG.0000000000000339
B
ilateral renal agenesis is a severe fetal anomaly occurring in 1 in 3,000 pregnancies.1 Previously considered uniformly fatal, affected fetuses die in utero from cord compression, or newborns die within hours of birth because of severe pulmonary hypoplasia. Case reports of monoamniotic twins who were discordant for bilateral renal agenesis have described See related editorial on page 411.
From the Johns Hopkins University School of Medicine, Baltimore, Maryland, and Legacy Maternal Fetal Medicine, Vancouver, Washington. Corresponding author: Jessica L. Bienstock, MD, MPH, Johns Hopkins University School of Medicine, 600 North Wolfe St., Baltimore, MD 21287; e-mail: [email protected]. Financial Disclosure The authors did not report any potential conflicts of interest. © 2014 by The American College of Obstetricians and Gynecologists. Published by Lippincott Williams & Wilkins. ISSN: 0029-7844/14
VOL. 124, NO. 2, PART 2, AUGUST 2014
normal pulmonary outcomes for the bilateral renal agenesis twin. However, all but one of these newborns have died as a result of renal failure within 12 days of life.2–4 One newborn was administered peritoneal dialysis but died at 2 months of age because of complications of the peritoneal dialysis.5 To date, there have been no long-term survivors of bilateral renal agenesis. Antenatal oligohydramnios, although not anhydramnios, of renal origin has been reported to have survival rates up to 70%, with 75% having normal cognitive and motor development.6
CASE Our patient is a 34-year-old woman, gravida 1 para 0, who presented to our hospital at 23 1/7 weeks of gestation for a second opinion. She specifically requested to discuss the possibility of serial amnioinfusion to prevent pulmonary hypoplasia. She had an uncomplicated antepartum course until diagnosis of bilateral fetal renal agenesis and anhydramnios at 20 weeks of gestation. There were no ultrasound examinations performed between the first trimester and the 20week scan, so the exact point at which anhydramnios occurred is unknown, although we surmise that this occurred early in the second trimester, when fetal urine production usually would be expected to account for the majority of amniotic fluid. Her medical history and family history were unremarkable. Obstetric ultrasonography revealed complete anhydramnios. Other abnormal ultrasonographic findings included bilateral renal agenesis, a narrow-appearing chest with ratio of thoracic circumference to abdominal circumference of 0.7 (normal5more than 0.8), ratio of heart circumference to chest circumference of 0.64 (normal5less than 0.6), dolichocephaly, bilateral clubbed feet, and no visible bladder or stomach. Fetal biometry was equivalent to 22 1/7 weeks of gestation, and the estimated fetal weight was 556 g. The patient was counseled that these findings were most consistent with bilateral renal agenesis and likely would result in Potter sequence and neonatal death from pulmonary hypoplasia. The patient was offered maternal blood testing for circulating cell-free fetal DNA but declined this testing. Based on our experience with performing amnioinfusions for patients with early-onset severe oligohydramnios, we discussed the possibility of serial amnioinfusion with the goal of preventing pulmonary hypoplasia. The patient met with a neonatologist to discuss issues related to prematurity and newborn respiratory distress, as well as a pediatric nephrologist to discuss the possibility of neonatal peritoneal dialysis as a bridge to eventual renal transplantation. Understanding the lack of clear evidence of a successful long-term outcome, the patient chose to undergo serial amnioinfusion. The first infusion was performed at 24 1/7 weeks of gestation. Under ultrasonographic guidance,
OBSTETRICS & GYNECOLOGY
413
a 20-gauge, 15-cm echotip needle was introduced into the amniotic cavity and 250 mL room temperature saline was infused to obtain a normal-appearing amniotic fluid volume (maximum vertical pocket of 3.9 cm). At the conclusion of the procedure, 10 mL indigo carmine was instilled into the amniotic cavity. After insertion of a vaginal tampon and ambulation, the tampon was removed and no blue dye was seen on the tampon, thus confirming that she did not have preterm premature rupture of membranes. The initial amnioinfusion allowed for improved visualization of the fetal anatomy. A normal fetal echocardiogram was obtained. Repeat ultrasound assessment 5 days later revealed a maximum vertical amniotic fluid pocket of 4.4 cm. Of note, the fetal stomach was visualized, and fetal breathing was seen as well. The fetal skull no longer appeared dolichocephalic, the thoracic-to-abdominal ratio was 0.8, and the ratio of heart circumference to chest circumference was 0.6. The feet still appeared clubbed, and no fetal bladder was visualized. The fetus had spontaneously turned from breech to vertex presentation. Over the subsequent 4 weeks, four additional weekly amnioinfusions were performed. The volume of saline infused was based on a goal of obtaining an amniotic fluid index of approximately 10 cm at the conclusion of each infusion. This calculated to approximately 15 mL per week of gestational age. At 28 1/7 weeks of gestation, the patient presented to her local hospital with preterm contractions. Betamethasone was administered to enhance fetal lung maturity. Contractions abated with subcutaneous terbutaline, and she was discharged home. At 28 4/7 weeks of gestation, preterm contractions developed again and she was admitted to the hospital. Magnesium sulfate was begun for fetal neuroprotection, and she was transferred to a hospital with a level 3 neonatal intensive care unit. One day later, after experiencing increasing contractions and pelvic pressure, spontaneous rupture of membranes occurred and soon thereafter she had a spontaneous vaginal delivery of a live female newborn with Apgar scores of 7 at 1 minute and 8 at 5 minutes. The newborn weighed 1,230 g and cried spontaneously at birth. A 10% placental abruption was noted. The newborn had excellent respiratory effort and required only nasal continuous positive airway pressure support. The newborn did not require surfactant administration or intubation. Neonatal examination was remarkable only for the absence of palpable kidneys. The newborn’s admission complete blood count revealed a white blood cell count of 9.3 with 14 bands, and she was treated empirically with intravenous gentamycin and ampicillin. Chest radiograph soon after birth revealed bilateral diffuse interstitial pulmonary infiltrates consistent with respiratory distress syndrome, but appropriate lung volumes. Ultrasonogram confirmed the prenatal diagnosis of bilateral renal agenesis, with no renal tissue identified in the renal fossae nor in any ectopic region of the pelvis. No urinary bladder could be
414
Bienstock et al
In Utero Therapy for Renal Agenesis
identified. Additionally, there was no stigmata of Potter sequence in the newborn. Because of limitations in the services available at the hospital of birth, the newborn was transferred to a major university hospital and began peritoneal dialysis at 36 hours of life. The newborn’s whole-genome array comparative genomic hybridization results were normal. The infant was discharged home at 19 weeks of age with daily home peritoneal dialysis. She required re-hospitalization 3 weeks later due to an obstruction of her peritoneal dialysis catheter that was complicated by the development of peritonitis. She was discharged home after replacement of the catheter and an additional 10-week stay. At the time of writing this article, the newborn is 9 months old and receiving daily home peritoneal dialysis, meeting her gestational age–adjusted milestones, and growing appropriately. The plan is to evaluate her for renal transplantation at 12 to 24 months of age. Written consent was obtained from the patient to allow for publication of this report.
COMMENT The etiology of lung hypoplasia associated with bilateral renal agenesis remains uncertain. The most likely explanation is that fetuses with bilateral renal agenesis lack fluid to draw into their lungs, allowing for the necessary canalicularization at 17 to 26 weeks of gestation,7 and have thoracic compression by the uterine walls because of anhydramnios. Studies of serial amnioinfusion with severe oligohydramnios attributable to preterm premature rupture of membranes have been promising regarding prevention of pulmonary hypoplasia.8–10 In a recent meta-analysis, Porat et al11 found an odds ratio of 0.17 (95% confidence interval 0.04–0.78) for development of pulmonary hypoplasia in patients enrolled in two observational studies and treated with amnioinfusion. However, that same meta-analysis found a nonsignificant odds ratio of 0.30 (95% confidence interval 0.05–1.7) for prevention of pulmonary hypoplasia in patients enrolled in three randomized controlled trials.11 Even if intrauterine death from cord compression and neonatal pulmonary hypoplasia can be prevented, dialysis as a bridge to renal transplantation is the only option if the newborn with bilateral renal agenesis is to survive. Peritoneal dialysis for newborns and infants recently has become a reality, with several case series estimating short-term survival (1–5 years) to range from 52 to 89%.12–14 Although peritoneal dialysis remains challenging in newborns, this technology is rapidly evolving and holds promise as a bridge to eventual renal transplantation. Among a Canadian cohort of
OBSTETRICS & GYNECOLOGY
children initiating renal replacement therapy before age 2 years, 65.5% underwent renal transplantation at a median age of 2.7 years; 26.4% died and 95.7% of these deaths occurred in patients who had not undergone transplantation. Mortality was highest when renal replacement was started before 3 months of age. Other issues in the pediatric renal transplant population include poor growth and immunosuppressant-related infections.12 Shortterm outcomes in prenatally diagnosed obstructive uropathy include a survival rate of 61% when fetuses are shunted in utero. Complications of shunting for obstructive uropathy include preterm delivery, chorioamnionitis, and intrauterine fetal demise.15 This is a novel report of short-term survival for an newborn with bilateral renal agenesis and anhydramnios. After serial amnioinfusion and spontaneous preterm delivery, the newborn displayed gestational age–appropriate lung function. Although prevention of pulmonary hypoplasia by serial amnioinfusion in no way cured the significant challenges of this newborn, it allowed her to become a candidate for neonatal peritoneal dialysis with the ultimate goal of undergoing renal transplantation. We acknowledge that the multiple invasive procedures to which the mother and, later, the newborn were subjected are painful, psychologically traumatic, and costly, and by no means provide guaranteed long-term normal outcomes. This case suggests that serial amnioinfusion may be discussed with patients as one option in the continuum of choices parents of fetuses with severe oligohydramnios attributable to fetal bilateral renal agenesis have to consider. REFERENCES 1. Woodward PJ, Kennedy A, Sohaey R, Byrne JLB, Oh KY, Puchalski MD. Diagnostic imaging—obstetrics. Salt Lake City (UT): Amirsys; 2011:2–28. 2. Klinger G, Merlob P, Aloni D, Maayan A, Sirota L. Normal pulmonary function in a monoamniotic twin discordant for bilateral renal agenesis: report and review. Am J Med Genet 1997;73:76–9.
VOL. 124, NO. 2, PART 2, AUGUST 2014
3. Cilento BG Jr, Benacerraf BR, Mandell J. Prenatal and postnatal findings in monochorionic, monoamniotic twins discordant for bilateral renal agenesis-dysgenesis (perinatal lethal renal disease). J Urol 1994;151:1034–5. 4. Mauer SM, Dobrin RS, Vernier RL. Unilateral and bilateral renal agenesis in monoamniotic twins. J Pediatr 1974;84: 236–8. 5. Perez-Brayfield MR, Kirsch AJ, Smith EA. Monoamniotic twin discordant for bilateral renal agenesis with normal pulmonary function. Urology 2004;64:589. 6. Klaassen I, Neuhaus TJ, Mueller-Wiefel DE, Kemper MJ. Antenatal oligohydramnios of renal origin: long-term outcome. Nephrol Dial Transplant 2007;22:432–9. 7. Kilbride HW, Yeast J, Thibeault DW. Defining limits of survival: lethal pulmonary hypoplasia after midtrimester premature rupture of membranes. Am J Obstet Gynecol 1996;175:675–81. 8. Ogunyemi D, Thompson W. A case controlled study of serial transabdominal amnioinfusions in the management of second trimester oligohydramnios due to premature rupture of membranes. Eur J Obstet Gynecol Reprod Biol 2002;102:167–72. 9. Garzetti GG, Ciavattini A, De Cristofaro F, La Marca N, Arduini D. Prophylactic transabdominal amnioinfusion in oligohydramnios for preterm premature rupture of membranes: increase of amniotic fluid index during latency period. Gynecol Obstet Invest 1997;44:249–54. 10. Tranquilli AL, Giannubilo SR, Bezzeccheri V, Scagnoli C. Transabdominal amnioinfusion in preterm premature rupture of membranes: a randomised controlled trial. BJOG 2005;112:759–63. 11. Porat S, Amsalem H, Shah PS, Murphy KE. Transabdominal amnioinfusion for preterm premature rupture of membranes: a systematic review and metaanalysis of randomized and observational studies. Am J Obstet Gynecol 2012;207:393.e1–e11. 12. Alexander R, Foster B, Tonelli M, Soo A, Nettell-Acquirre A, Hemmelgarn BR, et al. Survival and transplantation outcomes of children less than 2 years of age with end-stage renal disease. Pediatr Nephrol 2012;27:1975–83. 13. Genc G, Bicakci U, Gunaydin M, Tander B, Aygun C, Ozgaya O, et al. Temporary peritoneal dialysis in newborns and children: a single-center experience over five years. Ren Fail 2012;34:1058–61. 14. Vidal E, Edefonti A, Murer L, Gianoglio B, Maringhini S, Pecoraro C, et al. Peritoneal dialysis in infants: the experience of the Italian Registry of Paediatric Chronic Dialysis. Nephrol Dial Transplant 2012;27:388–95. 15. Freedman AL, Johnson MP, Gonzalez R. Fetal therapy for obstructive uropathy: past, present.future? Pediatr Nephrol 2000;14:167–76.
Bienstock et al
In Utero Therapy for Renal Agenesis
415
