(523) Early and late onset superimposed preeclampsia and adverse maternal outcomes.

Several studies have shown that the pathophysiology of early-onset superimposed preeclampsia (SIPE) and that of late-onset SIPE is different. We sought to examine adverse maternal outcomes of early-onset and late-onset SIPE.

Study Design:

This was a retrospective cohort study of pregnant patients with chronic hypertension who delivered at 22 weeks’ gestation or greater at an academic institution. Early-onset SIPE was defined as the onset of SIPE before 34 weeks. Late-onset SIPE was defined as the onset of SIPE after 34 weeks. The composite outcome was defined as a composite of maternal mortality, eclampsia, HELLP syndrome, placental abruption, pulmonary edema, and thromboembolic disease. Maternal outcomes were compared between patients with early-onset SIPE, late-onset SIPE, and without SIPE. We used multivariable logistic regression models to calculate adjusted odds ratios (aOR) with 95% confidence intervals (95%CI).

Results:

Of 881 patients, 148 (16.8%) had early-onset, 172 (19.5%) had late-onset SIPE, and 561 (63.7%) did not have SIPE. There were significant differences in proportions of obstetric complications including the composite outcome, eclampsia, HELLP syndrome, fetal growth restriction (FGR), and cesarean delivery across the groups (Table 1). Compared to patients with late-onset SIPE, those with early-onset SIPE had increased odds of the composite outcome (aOR 11.60; 95%CI 2.64-51.10), FGR (aOR 5.12; 95%CI 2.86-9.18), and cesarean delivery (aOR 4.20; 95%CI 2.38-7.40) (Table 2). Compared to patients without SIPE, those with early-onset SIPE were at increased odds of the composite outcome (aOR 5.11; 95%CI 2.50-10.44), FGR (aOR 3.46; 95%CI 2.30-5.21), and cesarean delivery (aOR 4.07; 95%CI 2.45-6.74). There were no differences in adverse maternal outcomes between patients with late-onset SIPE and those without SIPE.

Conclusion:

In patients with chronic hypertension, patients with early-onset SIPE had the highest odds of adverse maternal outcomes compared to those with late-onset SIPE and those without SIPE.