Polycystic ovary syndrome and risk of pre-eclampsia: A national register-based cohort study

Abstract

Objective: To explore whether the association between polycystic ovary syndrome (PCOS) and pre-eclampsia depends on treated clinical hyperandrogenism and whether PCOS is associated with different subtypes of pre-eclampsia. Design: Nationwide register-based cohort study. Setting: Sweden. Population: Nulliparous women with PCOS (n = 22 947) and non-PCOS controls (n = 115 272) giving singleton birth at ≥22 gestational weeks during 1997–2015. Treated clinical hyperandrogenism was defined as filled prescriptions of anti-androgenic drugs during 2005–2017 (n = 2301 among PCOS women). Methods: The risk of pre-eclampsia was estimated with conditional logistic regression, expressed as adjusted odds ratio (OR) with 95% confidence interval (CI). Adjustments were performed individually for confounders and predictors. Main outcome measures: Overall pre-eclampsia. Early/late (delivery <34/≥34 weeks) pre-eclampsia. Pre-eclampsia with or without a small-for-gestational-age (SGA) infant. Results: Compared with controls, women with PCOS had a 29% increased risk of pre-eclampsia (predictor adjusted OR 1.29, 95% CI 1.20–1.39), with similar risk estimates for PCOS women with and without treated clinical hyperandrogenism. The association between PCOS and early pre-eclampsia seemed stronger than its association with late pre-eclampsia (predictor adjusted OR 1.64 (95% CI 1.33–2.02) and 1.26 (95% CI 1.17–1.37). Additionally, the association seemed slightly stronger between PCOS and pre-eclampsia in women with an SGA infant than without. Conclusions: Women with PCOS face an increased risk for pre-eclampsia, especially early pre-eclampsia and pre-eclampsia with an SGA infant. We were unable to determine on the basis of available data, whether hyperandrogenism is associated with pre-eclampsia.