Socioeconomic deprivation and risk of early-onset pre-eclampsia in England: a national population-based cohort study

Objectives: To examine the association between small-area socioeconomic deprivation and risk of early-onset pre-eclampsia (diagnosed <34 weeks gestation) in England, and to assess the relative contributions of individual-level risk factors and variation between maternity care sites to observed inequalities. Design: Retrospective population-based cohort study. Setting: National Health Service (NHS)-funded maternity services in England between 1 January 2021 and 31 March 2025. Participants: 1,027,707 nulliparous pregnant women aged 13-60 years receiving NHS-funded maternity care in England with singleton pregnancies and non-missing deprivation data. Secondary analyses were conducted for 940,505 multiparous pregnant women. Main outcome measures: Early-onset pre-eclampsia, defined as diagnosis before 34 completed weeks of gestation. Results: Increasing socioeconomic deprivation was associated with higher odds of early-onset pre-eclampsia among nulliparous women across all regression models. In the confounder-adjusted model, each one-point increase in the continuous deprivation score (scaled 0-10) was associated with a 3.4% increase in odds of early-onset pre-eclampsia (adjusted odds ratio (aOR) 1.034, 95% confidence interval (CI) 1.027 to 1.041). Adjustment for theorized mediators attenuated the association modestly (aOR 1.023, 95% CI 1.017 to 1.030), while additional adjustment for hospital site further attenuated the association (aOR 1.016, 95% CI 1.009 to 1.023). Elevated BMI, circulatory disease, maternal age over 40 years, Black ethnicity, and endocrine/metabolic disease were among the strongest predictors of early-onset pre-eclampsia. Similar but stronger deprivation associations were observed among multiparous women. Associations between deprivation and late-onset pre-eclampsia were comparatively weak or absent after adjustment. Conclusions: Socioeconomic deprivation was associated with increased risk of early-onset pre-eclampsia in England, particularly among multiparous women. Both individual-level risk factors and variation between maternity care sites appeared to contribute to observed inequalities. These findings support the importance of combining targeted clinical risk reduction with efforts to reduce unwarranted variation in NHS maternity care delivery. Keywords: Maternity care, Pregnancy, Pre-eclampsia, Socioeconomic deprivation, Health equity, National Health Service