Towards the Development of a Conceptual Framework of the Determinants of Pre-Eclampsia: A Hierarchical Systematic Review of Social Determinants.

Background: Existing reviews of pre-eclampsia determinants have focused on clinical and genetic risk factors.

Objective: To evaluate social determinants for pre-eclampsia prevention.

Search strategy: Systematic searches were conducted from relevant electronic databases from inception of each database to 30th December 2024.

Selection criteria: Reviews and large cohort studies (≥ 1000 participants), published between 2013 and 2024, reporting quantitative associations between social determinant exposures and pre-eclampsia outcomes.

Data collection and analysis: Titles and abstracts, then relevant full-texts were reviewed by two reviewers, independently. Strength of association was evaluated as 'definite' (odds ratios [OR] or relative risk [RR] ≥ 3.00 or < 0.33), 'probable' (OR or RR 1.50-2.99 or 0.33-0.67), 'possible' (OR or RR 1.10-1.49 or 0.68-0.89), or 'unlikely' (OR or RR 0.90-1.09). Quality of the evidence was high, moderate, low, or very-low, using GRADE.

Main results: Twenty-seven publications found 24 associations of pre-eclampsia with socioeconomic status, social support/exclusion, healthcare access, and occupational and physical environmental factors. One association (polygamy) was definite (low-quality evidence). Probable associations included: work stress, lack of antenatal care and heat exposure in early pregnancy (high-quality evidence); prolonged occupational exposure to whole body vibrations or bending, distance to health facility, and UV-B radiation exposure (protective factor), all based on moderate-quality evidence; and neighbourhood deprivation, rotating work shifts, and Asian/Oceanian origins (protective factor), all based on low-quality evidence. There were 13 possible associations, which did not include education.

Conclusion: Our findings support recommendations to address climate change, strengthen occupational protection, and promote early antenatal attendance. Social determinants may be indicative of upstream factors (e.g., obesity) that increase likelihood of clinical risk factors for pre-eclampsia incidence and severity.