Doppler investigation of uteroplacental blood flow resistance in the second trimester: a screening study for pre‐eclampsia and intrauterine growth retardation

Abstract

Objective— To assess the screening properties of a mid-trimester uteroplacental Doppler scan in a normal unselected population. Design— A cross-sectional study measuring an averaged resistance index (AVRI) from four sites (left and right uterine and arcuate arteries) with continuous wave Doppler ultrasound. Setting— Routine booking ultrasound, King's College Hospital, London. Subjects— 977 women at 16–24 weeks gestation. Main outcome measures— Intrauterine death, birthweight, pregnancy-induced hypertension (PIH), antepartum haemorrhage. Results— There was a 96.5% follow-up. Pregnancies with high AVRI values had a higher prevalence of proteinuric hypertension, placental abruption, small-forgestational-age babies, and fetal loss. When AVRI was >95th centile, the overall risk of pregnancy complications was 67%, and the risk of a severe complication was 25%. However, the sensitivity of the test for these complications was only 13% and 21% respectively. The risk for an individual woman with a high AVRI of developing a complication was increased by up to 9.8 times. Conclusion— Although Doppler screening does detect a unifying defect leading to perinatal death, pre-eclampsia, growth retardation and placental abruption, the predictive values do not yet justify its introduction as a routine test.