Renal oligo- and anhydramnios: cause, course and outcome--a single-center study.

Purpose: To evaluate the outcome of patients with renal oligohydramnios and explore the impact of patient variables on outcome and prognosis.

Methods: A retrospective single-center study was conducted analyzing 104 pregnancies complicated by oligohydramnios of renal origin from 2001 to 2011. Statistical analysis was performed to assess the influence of pre- and postnatal data on pregnancy outcome, morbidity and mortality.

Results: Prenatal renal diagnoses were as follows: hydronephrosis/megaureter: n = 21 (20.2 %), aberrance in renal form or location: n = 7 (6.7 %), cystic renal disease: n = 28 (26.9 %), renal dysplasia: n = 24 (23.1 %), renal agenesis: n = 42 (30.4 %), posterior urethral valves: n = 11 (10.6 %). Hydronephrosis/megaureter and late onset of oligohydramnios were prognostic factors for fetal survival, whereas renal agenesis and associated anomalies had a negative impact on pregnancy outcome. Prenatal interventions did not improve prognosis.

Conclusions: Pregnancies complicated by renal oligohydramnios still have a poor outcome. Careful weighing of prognostic factors is necessary to decide about further therapeutic measures.