Conservative versus invasive management of symptomatic hydronephrosis in pregnancy: maternal and fetal outcomes

Abstract

Objective: The management of symptomatic hydronephrosis during pregnancy requires balancing maternal and fetal health. This exploratory retrospective study evaluated outcomes of conservative versus invasive intervention approaches in pregnant patients with symptomatic hydronephrosis. Methods: We conducted a retrospective analysis of pregnant patients with symptomatic hydronephrosis who underwent conservative management or invasive interventions. Groups were compared regarding demographics, gestational age at diagnosis, fetal birth weight, maternal renal function, and pregnancy-related complications. Results: The conservative (n = 52) and invasive intervention (n = 29) groups had comparable baseline characteristics, including maternal age (25.8 ± 4.7 vs. 27.0 ± 4.9 years, p = 0.290) and gestational age at diagnosis (24.1 ± 5.9 vs. 24.8 ± 5.8 weeks, p = 0.610). Birth weight was significantly higher with conservative management (3,289 ± 531 g vs. 3,045 ± 337 g, p = 0.029). Multivariable regression analysis adjusting for maternal age, gestational week, and gravidity showed no significant independent association with birth weight (β = 167.5 g, 95% CI: -55.5–390.5 g, p = 0.139), with the most significant difference observed in Grade 3 hydronephrosis (654 g, p = 0.055). Serum BUN levels were lower with invasive intervention (6.9 ± 1.0 vs. 7.5 ± 1.1 mg/dL, p = 0.020), though serum creatinine, a more specific renal function marker, showed no significant difference (p = 0.836). Rates of gestational hypertension and preeclampsia were comparable between groups. Conclusion: Both conservative and invasive management strategies appear feasible and clinically acceptable for symptomatic hydronephrosis during pregnancy, with no clinically significant differences in maternal or neonatal outcomes. Although a statistically significant difference in birth weight was observed, neonatal outcomes, including Apgar scores, were comparable between groups, and birth weights did not fall into categories of small for gestational age or fetal growth restriction. Invasive procedures may be necessary in severe cases with refractory symptoms, infection, or deteriorating renal function. Treatment selection should be individualized based on clinical severity rather than expected outcome differences.