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

Abstract

AbstractObjectiveTo 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.DesignNationwide register‐based cohort study.SettingSweden.PopulationNulliparous 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).MethodsThe 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 measuresOverall pre‐eclampsia. Early/late (delivery <34/≥34 weeks) pre‐eclampsia. Pre‐eclampsia with or without a small‐for‐gestational‐age (SGA) infant.ResultsCompared 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.ConclusionsWomen 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.