Predictors of eclampsia in California.

Objective: Eclampsia is a rare yet dangerous complication of the hypertensive disorders of pregnancy. The objective was to elucidate the predictors of eclampsia in a large cohort of pregnant women with gestational hypertension or preeclampsia.
Methods: This was a retrospective cohort study of 143 093 pregnancies with preeclampsia or gestational hypertension in California during 2005-2008 of which 1719 had eclampsia. Predictors included race/ethnicity, parity, chronic hypertension (CHTN), diabetes mellitus, gestational diabetes mellitus (GDM), preterm delivery <32 weeks, maternal age ≥ 35, maternal age ≤ 20, socioeconomic status, education, and <5 prenatal visits. Univariate and multivariate analyses were performed.
Results: Factors that increased the risk of eclampsia included Black (OR 1.46 [1.19-1.80]) and Hispanic race (OR 1.56 [1.35-1.79]), nulliparity (OR 1.59 [1.42-1.77]), maternal age ≤ 20 (OR 1.85 [1.61-2.11]), preterm delivery <32 weeks (OR 1.41 [1.16-1.70]), and <5 prenatal care visits (1.74 [1.46-2.07]). Factors that decreased the risk of eclampsia included CHTN (OR 0.06 [0.03-0.10]), GDM (OR 0.80 [0.67-0.96]), maternal age ≥ 35 (OR 0.70 [0.59-0.82]), and college education (OR 0.83 [0.74-0.94]).
Conclusions: Black and Hispanic race, nulliparity, maternal age ≤ 20, preterm delivery <32 weeks, and <5 prenatal care visits increase the risk of eclampsia while CHTN, GDM, maternal age ≥ 35, and college education are protective. The protective effect of CHTN is the most striking. The mechanisms are likely different and warrant further investigation.