Outcome following prenatal diagnosis of severe bilateral renal hypoplasia.

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.