233. Risk of cardiovascular mortality in women with a history of spontaneous preterm birth: A nationwide cohort study

Introduction Data suggest an association between a history of spontaneous preterm birth (sPTB) and cardiovascular disease (CVD) in later life. Therefore, we hypothesized that women with a history of sPTB have a higher cardiovascular mortality (CVM) risk. Methods Women who gave birth between 1995–2015 (registered in the National Birth Registry) were analyzed for death due to CVD through linkage with the National Death Registry. After excluding women with hypertensive pregnancy disorders and/or intra-uterine growth restriction, CVM for women with sPTB was analyzed prospectively in two different cohorts: including all births per woman and including only the first birth of a woman. Women with a sPTB were compared to women with no preterm birth. Cox-regression models with survival curves were executed. Results Of 1,476,048 parous women 6.9% had a history of sPTB. sPTB was associated with a 1.65- fold higher CVM risk (95% CI 1.34–2.04). Recurrent sPTB (HR 2.57; 95% CI 1.45–4.56) and sPTB under the 32 weeks gestational age (HR 2.59; 95% CI 1.64–4.10) were significantly associated with the highest CVM risk. In the 1,166,476 nulliparous women, 6.4% had a sPTB. sPTB was associated with a 1.38-fold higher risk for CVM (95% CI 1.02–1.87). In this cohort the highest CVM risk was also found in women with a sPTB  Conclusion These data suggest that sPTB is associated with CVM. The CVM risk is highest in women with recurrent sPTB and sPTB