INTRODUCTION
Preeclampsia (PE), which complicates 2-4% of pregnancies, is associated with a global annual rate of about 75,000 maternal deaths and 500,000 baby deaths.1,2 The risk for development of PE is related to several maternal characteristics, including age, weight, racial origin, method of conception, prior and family history of PE, and pre-existing medical conditions, such as chronic hypertension, diabetes mellitus and autoimmune disease.3
Studies from countries with populations that are of predominantly white racial origin have consistently reported that in minority groups, such as women of black racial origin, the incidence of PE is increased.4-19 In a small number of studies the incidence of PE in women of East Asian racial origin tended to be lower than in white women, whereas in South Asian women the incidence tended to be similar to that in white women.9,12,15,16,20-22However, in most of these studies the observed relative incidence of PE was not adjusted for confounding factors in maternal characteristics and medical history. In a previous study of 76,158 singleton pregnancies with a live fetus at 11+0 to 13+6weeks, we adjusted for confounders and reported that in women of black and South Asian racial origin, but not in East Asian women, the incidence of PE was higher than in white women.23
The objectives of this extended study of 168,966 singleton pregnancies with a live fetus at 11+0 to 13+6weeks are first, to examine the association between maternal racial origin and PE after adjustment for confounding factors in maternal demographic characteristics and medical history in the data from the Fetal Medicine Foundation (FMF), and second, to carry out a systematic review of the literature and meta-analysis of all studies on this topic.