Although fewer pregnant women today die from preeclampsia, the condition remains a leading cause of preterm delivery and neonatal problems and deaths. Preeclampsia tends to run in families, and is characterized by an abrupt rise in blood pressure, leaking of protein into urine, and swelling of the hands, feet, and face. A new study, supported in part by the Agency for Healthcare Research and Quality (HS10856), suggests that both maternal and paternal ethnicity, as well as parental ethnic discordance, affect rates of preeclampsia.
Researchers retrospectively studied 127,544 women at low risk for preeclampsia who delivered babies from 1995 to 1999 within a managed care organization. They calculated rates of preeclampsia based on maternal, paternal, and combined ethnicity.
Overall, about 4 percent of the women studied were diagnosed with preeclampsia. The parent who exerted the larger effect on risk of preeclampsia appeared to vary by ethnicity. Baseline rates of preeclampsia were 5.2 percent among black women, 4 percent among Hispanics, 3.9 percent among Native American women, 3.8 percent among white women, and 3.5 percent among Asian women. These differences persisted after controlling for maternal age, number of children, education, and gestational age.
However, when paternal ethnicity was controlled for separately, the effect of black maternal ethnicity increased slightly while the difference in the rate of preeclampsia among Asian women disappeared. Asian paternity was found to be associated with the lowest rate of preeclampsia (3.2 percent). Further, parental ethnic discordance (mother and father have different ethnicities) was associated with a 13 percent increase in the rate of preeclampsia, with the exception of Native American mothers. When parental ethnicity among Native Americans was the same, it was associated with a higher rate of preeclampsia (9.7 percent) as compared with different ethnicity (3.3 percent).
See "Maternal ethnicity, paternal ethnicity, and parental ethnic discordance: Predictors of preeclampsia," by Aaron B. Caughey, M.D., M.P.P., Naomi E. Stotland, M.D., A. Eugene Washington, M.D., M.Sc., and Gabriel J. Escobar, M.D., in the July 2005 Obstetrics & Gynecology 106(1), pp. 156-161.