Preeclampsia and neonatal outcomes in chronic hypertension: comparison between white and black women.

We compared the incidence of preeclampsia and neonatal outcomes in 208 white (born in Canada) and 74 black (born in Haiti) women with mild chronic hypertension. Controls included 17,677 white and 2,400 black normotensive women delivered in the same center between 1987 and 1991. Superimposed preeclampsia (32.4% vs 14.9%; p < 0.01), perinatal mortality (9.5% vs 2.9%; p < 0.05) and prematurity (32.4% vs 19.7%; p < 0.05) were more frequent in black than in white women with chronic hypertension. Within both races, chronic hypertensive women with superimposed preeclampsia demonstrated higher rates of perinatal mortality and morbidity than controls. White chronic hypertensive women without preeclampsia and controls had similar rates of perinatal mortality as compared to black study participants and controls (2.3% vs 1.4%), small-for-gestational-age newborns (10.7% vs 7.8%) and prematurity (12.4% vs 15.3%). Compared to black controls, black chronic hypertensive women without preeclampsia had higher rates of perinatal mortality (1.2% vs 8.0%; p < 0.001) and prematurity (9.0% vs 18.0%; p < 0.05). These data provide evidence of ethnic differences in perinatal outcomes in chronic hypertensive women that are not explained only by superimposed preeclampsia.