Neonatal survival after serial amnioinfusions for fetal bilateral renal agenesis: report from the raft trial

Abstract

Bilateral renal agenesis (BRA) in the fetus leads to anhydramnios and lethal pulmonary hypoplasia. We report obstetric outcomes and neonatal survival/complications for pregnancies undergoing serial amnioinfusions (AIs) in the completed BRA arm of the Renal Anhydramnios Fetal Therapy (RAFT) trial (NCT03101891). RAFT is a nonrandomized prospective clinical trial conducted at 9 North American Fetal Therapy Network sites to assess the safety and efficacy of serial AIs to treat BRA. The primary outcome was postnatal survival ≥ 14 d and dialysis access placement. Inclusion required ultrasound (US) confirmed isolated BRA, normal genetic testing, and first therapeutic AI prior to 26 w gestational age (GA). AIs were done with US guidance to maintain adequate amniotic fluid volume during pregnancy. All delivered at a RAFT center. Enrollment was suspended in July 2022 after Data Safety Monitoring Board review of neonatal morbidity and survival data. Twenty maternal-fetal pairs underwent serial AIs (Figure). There were 18 (90%) livebirths, median GA 32 w [IQR 31.8, 34]. Obstetric complications included preterm prelabor rupture of membranes (60%), chorioamniotic membrane separation (30%) and bleeding (20%). 78% (95% CI, 0.57-0.99) (n=14) of neonates survived to ≥ 14 d and had placement of dialysis access (Table). Factors associated with survival to the primary endpoint included more AIs, GA at birth ≥ 32 w, and higher birthweight (BW). 5/14 infants who met the primary outcome survived to discharge on peritoneal dialysis (PD) at a median age of 25 w [IQR 12, 32]; 2 of the 5 died after discharge. 3 of the 5 infants discharged home and one who remains in the NICU sustained strokes. Serial AIs initiated before 26 w in pregnancies with BRA mitigated lethal pulmonary hypoplasia. Survival to discharge on PD and beyond was considerably lower than survival to ≥ 14 d and strongly associated with GA and BW, highlighting the additional morbidity and mortality independent of lung function for infants lacking kidneys. Recruitment for the non-BRA fetal renal failure arm of the trial continues.View Large Image Figure ViewerDownload Hi-res image Download (PPT)