Outcome of pregnancies complicated by oligohydramnios or anhydramnios of renal origin

Objective: To evaluate the outcome of fetuses with oligohydramnios due to kidney anomalies. Methods: A retrospective study was performed of all pregnancies diagnosed with oligohydramnios and associated kidney anomalies during the period 2000-2008. Outcome included pregnancy outcome, mortality, and morbidity. Morbidity included renal function based on the glomerular filtration rate (GFR) during follow-up. Results: A total of 71 pregnancies were evaluated; 36 fetuses presented on ultrasound with cystic dysplasia, 15 with polycystic kidney disease (PKD) and 20 with hydronephrosis. Twenty-three (32%) had associated anomalies. In 49 fetuses (69%), the diagnosis had been made before 24 weeks of gestational age (GA); 41 of those pregnancies were terminated. Twenty-five neonates were live born: 10 survived, 15 died. Prognostic factors for survival included GA at diagnosis (32.2 weeks for survivors vs 28.1 weeks for non-survivors; P = 0.02), diagnosis of hydronephrosis (7 in the survivors vs 4 in the non-survivors: P = 0.05), isolated anomaly (9 in the survivors vs 7 in the non-survivors: P = 0.04). Severity of oligohydramnios (1 case of anhydramnios in the survivors vs 7 in the non-survivors: P = 0.08) was not significant. The 1-year GFR was below 50 mL/min.1.73 m ² in four of the ten survivors. Conclusion: The prognosis of early onset renal oligohydramnios is poor. Predictive determinants of survival are: GA at diagnosis, nature of renal anomaly (hydronephrosis vs other), and presence of associated anomalies.