Is postpartum preeclampsia a continuation of intrapartum preeclampsia? Maternal risk factors in intrapartum vs. postpartum preeclampsia: a retrospective cohort study

To compare maternal characteristics and risk factors associated with intrapartum and postpartum preeclampsia in relation to pregnancies without preeclampsia. This retrospective cohort study used data from 265,068 pregnancies (2013–2024) categorized into three groups: no preeclampsia (96.9%), intrapartum preeclampsia (2.8%), and postpartum preeclampsia (0.2%). Multivariate logistic regression models identified risk factors associated with intrapartum preeclampsia and postpartum preeclampsia, with no preeclampsia as the reference group. Postpartum preeclampsia shared remarkably similar risk factors with intrapartum preeclampsia after adjusting for confounders. Key associations included maternal age (adjusted odds ratio (aOR) = 1.03, 95% confidence interval (CI): 1.02–1.03 for intrapartum pre-eclampsia and aOR = 1.03, 95% CI: 1.03–1.04 for postpartum preeclampsia); obesity (aOR = 1.50, 95% CI: 1.41–1.59 for intrapartum preeclampsia and aOR = 1.51, 95% CI: 1.43–1.61 for postpartum preeclampsia), and nulliparity (aOR = 2.20, 95% CI: 2.05–2.35 for intrapartum preeclampsia and aOR = 2.12, 95% CI: 1.99–2.27 for postpartum preeclampsia). Additional associations included diabetes (aOR = 1.55, 95% CI: 1.36–1.76 for intrapartum preeclampsia; aOR = 1.51 and 95% CI: 1.33–1.71 for postpartum preeclampsia); hypertension (aOR = 4.02, 95% CI: 3.50–4.59 for intrapartum preeclampsia and OR = 4.01, 95% CI: 3.51–4.56 for postpartum preeclampsia), and gestational hypertension (aOR = 2.46, 95% CI: 2.21–2.74 for intrapartum pre-eclampsia and aOR = 2.46, 95% CI: 2.22–2.73 for postpartum preeclampsia. Postpartum and intrapartum preeclampsia share similar clinical and demographic risk factors, suggesting postpartum preeclampsia may be a continuation of preeclampsia rather than a distinct clinical entity. Identifying shared risk factors can facilitate early diagnosis and intervention, critical for reducing maternal morbidity and mortality.