Outcome following prenatal diagnosis of severe bilateral renal hypoplasia

Abstract

Objective: The aim of this research was to evaluate the outcome and prognostic value of fetal serum β2-microglobulin in case of prenatal diagnosis of severe bilateral renal hypoplasia.

Methods: Cases of hypoplastic kidneys were detected on ultrasound and referred to our laboratory for determination of fetal blood β2-microglobulin, over a 12-year period. Prenatal prognostic assessment was based upon amniotic fluid volume and fetal serum β2-microglobulin (cut-off: 5 mg/L). Outcome measures were postnatal renal function or renal pathological features when termination of pregnancy (TOP) and genetic studies were performed.

Results: A total of 34 cases were identified; 13 (38%) were liveborn and 21 (62%) underwent TOP. Renal hypoplasia was confirmed postnatally in all cases. Oligohydramnios/anhydramnios was observed in 30/34 (88%) cases. Associated genetic or anatomical anomalies were found in 8/34 (24%) cases. Renal function of liveborn infants was normal in 4/13 cases. Renal lesions were observed in all TOPs (21/21 cases). Overall, 30/34 (88.2%) cases had a poor outcome. β2-microglobulin accurately predicts poor renal outcome in 27/31 (87.1%) cases. β2-microglobulin was not interpretable in three cases due to amniotic fluid contamination. The prognostic value of β2-microglobulin was similar to that of amniotic fluid volume assessment.

Conclusion: Hypoplastic kidneys complicated by oligohydramnios/anhydramnios are associated with poor outcome. Fetal serum β2-microglobulin and oligohydramnios both predicted poor outcome.