THE USE OF DOPPLER VELOCIMETRY OF THE UMBILICAL ARTERY BEFORE 24 WEEKS GESTATION TO SCREEN FOR HIGH-RISK PREGNANCIES

Objective. To describe the prevalence and natural history of absent en d-diastolic velocities (AEDV) in the umbilical artery of the fetus bet ween 16 and 24 weeks' gestation, and to evaluate its role as a screeni ng test. Design. Population-based descriptive study. Setting. Tygerber g Hospital, Tygerberg, South Africa. The hospital serves a population from the lower socio-economic bracket. Subjects. Doppler velocimetry w as performed at routine ultrasound examinations for confirmation of ge stational age in 496 women. Main outcome measures. The occurrence of p erinatal death, small-for-gestational-age (SGA) babies and proteinuric hypertension. Results. Forty-four (8,9%) patients had AEDVs at the fi rst examination, but AEDV persisted in only 1. In this case, severe pr oteinuric hypertension developed unexpectedly at 29 weeks' gestation a nd the fetus needed delivery because of persistent late decelerations of the fetal heart rate pattern. There was a significant association b etween the group with AEDV at first examination and the development of proteinuric hypertension (P <0,05), but no association with SGA babie s. The association with proteinuric hypertension was too weak to be of clinical use. Conclusion. Doppler velocimetry of the umbilical artery , performed along with routine ultrasound examination to confirm gesta tional age, is not of use as a screening test for identifying high-ris k pregnancies.