Trends and Predictors of Eclampsia among Singleton and Multiple Gestations in the United States, 1989-2018.

Objective: To examine temporal trends of eclampsia by plurality in the US spanning three decades (1989-2018); and to investigate risk factors for eclampsia among singleton and multiple pregnancies in the US during the study period. Study design: We conducted a retrospective cohort study using the Natality data files, including information on all births within the gestational age of 20-42 weeks from 1989 through 2018. We used joinpoint regression analysis to evaluate trends in rates of eclampsia over the study period. We employed logistic regression models to examine the association between plurality and eclampsia after adjusting for socio-demographic and gestational factors. Main outcome measures: The primary outcome was eclampsia among singleton and multiple pregnancies. Findings: There was a 2.8% (95% CI:-5.4,-0.1) average annual reduction in eclampsia rates among singletons, whereas among multiples there was a decline of about 3.7% (95% CI:-6.4,-1.0) annually. Mothers with multiple pregnancies had three-fold increased adjusted odds (OR = 95% CI: 2.95-3.21) of experiencing eclampsia when compared to those with singleton gestations. Non-Hispanic (NH) Black mothers with singletons had 37% greater adjusted odds of developing eclampsia than their NH-White peers (95%CI: 1.33-1.42). Conclusion: There was an overall decreasing trend in eclampsia incidence in the US from 1989 to 2018, regardless of plurality. The occurrence of eclampsia was associated with plurality, race/ethnicity, maternal age and maternal BMI. Given the heterogeneity in clinical presentations of eclampsia, personalized/standardized risk prediction models are needed to enable consistent diagnosis and timely intervention.