BALTIMORE — Meredith Atkinson, MD, MHS, presented findings from the Renal Anhydramnios Fetal Therapy (RAFT) study, indicating that serial amnioinfusions during pregnancy improved survival outcomes for neonates with anhydramnios due to fetal kidney failure. The nonrandomized study found that over a third of infants born after this intervention avoided death from underdeveloped lungs.

The study screened and enrolled participants from 2018 to 2025 across 13 U.S. fetal intervention centers, focusing on maternal-fetal pairs with anhydramnios due to fetal kidney failure without bilateral renal agenesis. The cohort included 34 pregnant individuals with a median age of 30 years. Thirty-two pregnant individuals chose the intervention, while two opted for expectant management.

Of the 32 pregnancies that received the intervention, 29 resulted in live births. The intervention group underwent ultrasound-guided percutaneous amnioinfusions with warmed isotonic solution under local anesthesia. These procedures began before 26 weeks' gestation to maintain a normal amniotic fluid index. The intervention did not result in unexpected obstetric complications for mothers.

Nineteen neonates survived at least 14 days with dialysis access placement, meeting the study's primary endpoint. Survival rates showed a decline from 58.6% at 30 days to 48% at 90 days. Fourteen infants survived to hospital discharge at a median age of 4.7 months, though three infants died after discharge.

"This study confirmed that serial amnioinfusions represent a feasible intervention that can alter the fatal prognosis of midtrimester anhydramnios by mitigating pulmonary hypoplasia in most neonates," Atkinson said. "However, this path is burdened by prematurity and long-term morbidity, underscoring the necessity of thorough, nuanced counseling for families considering this intervention."

Among the 11 surviving infants to date, seven have received a kidney transplant. Six of these 11 children experienced strokes, including one spinal stroke. Families who provided feedback reported chronic anxiety and frequently worried about their child's future. Three-quarters of these families noted that family activities required more time and effort, and most of the children suffered from low energy.

Survivors received a median of 14 amnioinfusions, compared to seven for nonsurvivors. The time from the first amnioinfusion to preterm prelabor rupture of membranes was 63.5 days for those reaching the endpoint, versus 29 days for those who did not. Atkinson added, "Prenatal amnioinfusions do not guarantee respiratory survival in all neonates, and the likelihood of respiratory complications (e.g., pulmonary hemorrhage) in survivors should also be reviewed during prenatal counseling."

The study's limitations include its small sample size and a requirement for participants to have adequate insurance coverage at enrollment. Postnatal care was not standardized across the trial sites.