Epidemiology of eclampsia.

The purpose of this study was to examine the risk of eclampsia in relation to several maternal characteristics and exposures, including demographic characteristics, reproductive history, and tobacco use during pregnancy. A case control study was conducted using data for all singleton births from the Washington State birth certificates for 1984-1990. In the check box feature employed by these certificates, eclampsia is listed under maternal conditions. Risk estimates, adjusted for various confounders, were calculated comparing eclampsia among exposed versus unexposed women. The risk of eclampsia was elevated in women without prenatal care, those with weight gain of more than thirty pounds during pregnancy, nulliparous women, and those with chronic hypertension. The association with tobacco smoking were inverse and dose related. Women's race, urban or rural place of residence, history of pre-term births, and anemia were not associated with eclampsia. Our data reaffirm the importance of prenatal care, and provide further evidence of an inverse relationship with prenatal smoking. As eclampsia and pre-eclampsia are important pregnancy complications, further research is needed to explore their possible causes.