IntroductionEven though systemic vasculitides (SV) 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 SV. This study aims to evaluate the risk of hypertensive disorders and PTB amongst pregnant women with SV, and to identify associated risk factors.MethodUsing the French health insurance data warehouse, we conducted a nationwide cohort study including all pregnancies between 2013 and 2018 in women with SV. Theses pregnancies were matched to pregnancies among women without SV. We estimated hypertensive disorders’ risk and PTB risk during pregnancy among women with SV and we investigated associated risk factors using a nested case‐control design.ResultsAmid 3,155,723 pregnancies, we identified 646 pregnancies in women with SV, matched to 3,230 controls. SV were significantly associated with hypertensive disorders (OR 1.7, 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 SV 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.ConclusionAbout one over seven pregnancies in women with SV is associated with hypertensive disorders or preterm birth. The occurrence of vasculitides flare was associated with these complications. Our findings support the importance of pre‐pregnancy counselling to ensure disease stability.image