Antenatal ultrasonography to detect fetal renal abnormalities: a prospective screening programme

Abstract

Objective: To evaluate screening for abnormalities of the fetal renal tract by ultrasonography and to determine the incidence of such abnormalities in a population.

Design: A 12 month prospective population study. Follow up of infants to between 9 and 18 months.

Setting: A district general hospital.

Participants: 6292 Pregnant women reaching 28 weeks' gestation within the study period.

Interventions: Antenatal ultrasound scanning was offered to all of the women. Babies in whom an abnormality of the renal tract had been detected antenatally underwent ultrasound scanning at the end of the first week. If the abnormality was confirmed contrast radiography was performed.

End point: Confirmation of suspected renal abnormality by postnatal investigations. Detection of abnormality in children thought to be normal antenatally.

Measurements and main results: Of the 92 babies who had abnormal antenatal scans, 42 had abnormalities confirmed postnatally. Four of them died and 21 had had or were awaiting an operation at 18 months' follow up. Seven children had renal abnormalities that were missed antenatally. The incidence of abnormalities detected by screening antenatally was 0.65%, and the overall incidence at 18 months' follow up was 0.76%.

Conclusions: The incidence of structural renal abnormalities in babies is higher than reported previously. Antenatal ultrasonography is an effective way of detecting such abnormalities.