Spontaneous Preterm Birth and Subsequent Cardiovascular Mortality: Linked Registry Cohort Study.

Abstract

Determine the cardiovascular mortality risk in women with a history of spontaneous preterm birth. Population-based cohort study. The Netherlands. We used data-linkage between the National hospital Birth Registry and the National Death Registry. Data of women with a first birth between 1995 and 2015 were linked with the National Death Registry until 2017. Cardiovascular mortality (CVM) was analysed both in women with any type of PTB and in women with a spontaneous PTB (defined as PTB without a hypertensive disorders of pregnancy and/or fetal growth restriction). Subgroup analysis was performed for spontaneous PTB < 32 weeks. The cohort consisted of 1 166 476 women of whom in total 9.4% had a PTB (n = 109 935) and 6.4% (n = 74 722) had a spontaneous PTB. Median follow-up time was 11.3 years (IQR 6.1-16.4). Women with any type of PTB as well as women with a spontaneous PTB had a higher CVM risk compared to women with a term birth (n = 137; aHR 1.94; 1.61-2.33 and n = 48; aHR 1.38, 95% CI 1.02 to 1.87, respectively). Women with a spontaneous PTB 22-32 weeks GA had the highest CVM risk (n = 13; aHR 3.19; 95% CI 1.84-5.56) compared to women with a first term birth. Women with a history of a spontaneous PTB are at elevated risk for CVM, although to a lesser extent than women with a PTB related to HDP or FGR. Specifically, women with an early spontaneous PTB < 32 weeks GA had an elevated CVM risk. We hypothesize that the elevated cardiovascular risk might apply only to a vascular mediated subgroup of spontaneous PTB.