RISK-FACTORS FOR PREECLAMPSIA IN NULLIPAROUS WOMEN IN DISTINCT ETHNIC-GROUPS - A PROSPECTIVE COHORT STUDY

Objective: To determine whether baseline characteristics during early pregnancy, proposed as potential risk factors for preeclampsia, show d ifferences in prevalence and effects within distinct ethnic groups. Me thods: In a prospective cohort study of 2413 healthy nulliparous women from eight midwives' practices, we analyzed risk factors for preeclam psia (maternal age, body mass index, blood pressure at booking, smokin g habit, and abortion history) in white, Mediterranean, Asian, and bla ck women. In a univariate analysis, we estimated the relative risk of preeclampsia for the baseline variables and for ethnicity. In a multiv ariate analysis, we evaluated the simultaneous effect of the baseline variables in white (n = 1641) and black (n = 317) women. Results: Sign ificant differences were found in the prevalence of the risk factors i n different ethnic groups. In the univariate analysis, the relative ri sk (RR) of preeclampsia in black women was 2.4 (95% confidence interva l [CI] 1.1, 5.6) compared with white women. In the multivariate analys is in white women, the adjusted RR of preeclampsia for a diastolic blo od pressure at booking above 70 mmHg was 4.4 (CI 0.9, 20.8). Among bla ck women, the adjusted RR of preeclampsia was increased for high mater nal age (RR 1.2; CI 1.0, 1.4), but not for a diastolic blood pressure at booking above 70 mmHg (RR 0.8; CI 0.2, 3.9). Conclusion: In studies of risk factors for preeclampsia, black women should be analyzed sepa rately from white women. (Obstet Gynecol 1998;92:174-8. (C) 1998 by Th e American College of Obstetricians and Gynecologists.)