Risk of Primary Cesarean Delivery in Women With Pregnancy-Associated Hypertension [7C

Abstract

INTRODUCTION: Despite the lack of evidence supporting cesarean delivery (CD) in the setting of pregnancy-associated hypertension (PAH), women with this diagnosis continue to have high CD rates. The aim of this study is to determine whether the higher rate of primary CD among women with PAH can be explained by the presence of other known CD risk factors. METHODS: A retrospective cohort study of singleton, vertex, nulliparous women delivering between 34 and 42 weeks using the 2013 US National Vital Statistics Report dataset. Rates of primary CD in women with and without PAH were compared. Multivariate logistic regression predicted CD after controlling for known risk factors, including advanced maternal age (AMA), race/ethnicity, gestational age, pre-pregnancy BMI, US residency, insurance type, prenatal care, diabetes, and eclampsia. RESULTS: We analyzed 1,103,999 women, including 94,332 women diagnosed with PAH. The unadjusted CD rate in women with PAH was 41.3% compared to 26.9% in those without PAH (p < 0.01). Each analyzed risk factor was significantly associated with CD (Table). However, even after controlling for these risk factors, the predicted probability of CD in a woman with PAH would be 37.2% vs 26.5% without PAH (p < 0.01). PAH remained an independent predictor for CD (aOR 1.68 [95% CI 1.65-1.71]). CONCLUSION: After controlling for other risk factors, diagnosis of PAH alone is a significant risk factor for CD, likely reflecting a widespread practice that is not supported by the most recent clinical evidence. Women with PAH may therefore represent an important target population for efforts that aim to reduce primary CD rates.