Prenatal and Early Postnatal Outcomes for Fetuses with Anatomic or Functional Renal Agenesis.

Introduction The advent of novel fetal interventions has increased interest in fetal intervention for previously "lethal" anomalies such as bilateral renal agenesis or other congenital anomalies of the kidney and urinary tract (CAKUT) associated with in utero renal failure. While there have been rare reports of successful births following intervention in these cases, there is a paucity of data regarding the risks, benefits, and outcomes of intervention. To address this gap, this study presents our experience with fetal intervention for anatomic or functional renal agenesis. Case Presentation A retrospective review was conducted for patients referred to the Colorado Fetal Care Center (CFCC) between 2013-2019 for evaluation of CAKUT anomalies. Eligibility was determined by a multidisciplinary team. Amnioinfusion was scheduled prior to 24 weeks gestation, with normal saline or lactated ringers infused as needed to obtain a "normal" amniotic fluid volume. During this time period, a total of five cases received fetal amnioinfusion for treatment of bilateral renal agenesis or bladder outlet obstruction. All five cases reached birth. 3/5 cases expired on day one of life. 1/2 of the remaining infants expired at three months secondary to peritoneal dialysis failure. The remaining infant is 4 years. Developmentally, she is on track with cognitive and language skills but is behind with general motor skills. We observed a 30-day mortality of 60% and one-year mortality of 80%. Conclusions Individuals carrying a pregnancy complicated by CAKUT anomalies face a difficult choice when considering intervention. Morbidity and mortality remain high at this stage of this evolving therapy, including difficulty with retaining infused intraamniotic fluid > 72 hours and complications with peritoneal dialysis after birth. The surviving infant in this case series is 4 years. She currently awaits renal transplantation. These findings reinforce that treatment of these cases should remain experimental and large-scale multicenter trials are needed to determine the optimal indications for prenatal intervention.