Objective: Compare short-term urologic outcomes with delivery timing in fetuses with severe hydronephrosis.
Methods: An ultrasound database was queried for severe hydronephrosis. Cases were categorized into late preterm/early term (36 0/7 - 38 6/7 weeks) and full term (39 0/7 weeks or greater) groups. Baseline characteristics were compared using standard statistical methods. Spearman's correlation analysis was performed for grade and severity of hydronephrosis on first postnatal ultrasound with gestational age at delivery.
Results: Of 589 cases, 79 (33 late preterm/early term, 46 full term) met criteria. Baseline characteristics were similar between groups. Spearman's correlation coefficients (rs) indicated that increased postnatal Society for Fetal Urology grade, rs= -0.26 (95% CI [-.48, -.002]), and severity of hydronephrosis, rs= -0.39 (95% CI [-.59, -.14]), both correlated with earlier delivery.
Conclusion: Late preterm/early term delivery resulted in worse short-term postnatal renal outcomes. Unless otherwise indicated, delivery for fetal hydronephrosis should be deferred until 39 weeks.
Keywords: Fetal hydronephrosis; delivery timing; pelviectasis; pyelectasis.