Risk of Hypertensive Disorders and Preterm Birth in Pregnant Women With Systemic Vasculitides: A Nationwide Population-Based Cohort Study

Objective. Even though systemic vasculitides (SVs) affect primarily patients over 50 years of age, they can occur among women of childbearing age. Preterm birth (PTB) and hypertensive disorders are frequent complications of pregnancy in SVs. This study aims to evaluate the risk of hypertensive disorders and PTB among pregnant women with SVs, and to identify associated risk factors. Method. Using the French health insurance data warehouse, we conducted a nationwide cohort study including all pregnancies between 2013 and 2018 in women with SVs. Theses pregnancies were matched to pregnancies among women without SVs. We estimated risk of hypertensive disorders and PTB risk during pregnancy among women with SVs and investigated associated risk factors using a nested case-control design. Results. Among 3,155,723 pregnancies, we identified 646 pregnancies in women with SVs, matched to 3,230 controls. SVs were significantly associated with hypertensive disorders (odds ratio [OR] 1.7, 95% confidence interval [95% CI] 1.3-2.2) and PTB (OR 1.8, 95% CI 1.4-2.3). Chronic renal failure before pregnancy, history of or treated arterial hypertension, the occurrence of vasculitides flare during pregnancy, and the subgroup of SVs were independently associated with the occurrence of hypertensive disorders. Maternal age at delivery, chronic renal failure before conception, and the occurrence of vasculitides flare during pregnancy were independently associated with the occurrence of PTB. Conclusion. About one of seven pregnancies in women with SVs is associated with hypertensive disorders or preterm birth. The occurrence of vasculitides flare was associated with these complications. Our findings support the importance of prepregnancy counseling to ensure disease stability.