Screening with a uterine Doppler in low risk pregnant women followed by low dose aspirin in women with abnormal results: a multicenter randomised controlled trial

Objectives To assess whether systematic screening with an uterine artery Do ppler in low risk pregnant women followed by the prescription of low dose a spirin in cases with abnormal results reduced the incidence of intrauterine growth restriction and pre-eclampsia. Design A multicentre randomised trial. Population 3317 low risk pregnant women. In the Doppler group, the uterine artery Doppler was performed between 20 and 24 weeks. Women with abnormal r esults received 100 mg of aspirin daily until the 35th week. Main outcome measures Intrauterine growth restriction was defined as birthw eight below the tenth and the third centile according to gestational age. P re-eclampsia was defined as hypertension associated with proteinuria > 0.5g /L. Results Intrauterine growth restriction, whether defined by the third or te nth centile, did not differ significantly between the two groups (RR = 1.22 [0.73 - 2.04] and 1.18 [0.93 - 1.51] respectively). Screening with uterine artery Doppler did not affect birthweight or any of the criteria of perina tal morbidity. There was no effect on the incidence of pre-eclampsia (RR = 1.99 [0.97 - 4.09]) or hypertensive disorders. These results were the same for nulliparae and multiparae. Conclusions There is no justification for screening with uterine artery Dop pler in a low risk population, even if abnormal results are followed by asp irin treatment and increased prenatal surveillance. Future studies must ass ess predictive tests that can be performed early in pregnancy and can ident ify populations at very high risk of pre-eclampsia and intrauterine growth restriction. Only when all of these conditions are fulfilled, aspirin or ot her treatments may prove its efficacy.