Cardiovascular disease risk in women with a history of spontaneous preterm delivery: A systematic review and meta-analysis

Background Increasing evidence suggests a relation between having had spontaneous preterm delivery and cardiovascular disease in the future. We performed a systematic review and meta-analysis to assess the relation between a history of spontaneous preterm delivery and risk of ischaemic heart disease (IHD), stroke or overall cardiovascular disease (CVD). Methods We carried out a systematic search in Medline (from 1966 to 17 July 2014) and Embase (from 1980 to 17 July 2014). We included studies with a cohort design assessing the relation between spontaneous preterm delivery and fatal or nonfatal IHD, stroke, or overall CVD. IHD, stroke and CVD were assessed through linkage with national registries. Hazard ratios (HRs) were pooled using a random-effects model. Results Of the 10 cohort studies included; sample sizes ranged from 3706 to 923,686 women and follow-up ranged from 12-35 years. Spontaneous preterm delivery was related to an increased risk of developing or dying from IHD (HR 1.38, 95% confidence interval (CI) 1.22-1.57), stroke (HR 1.71, 95% CI 1.53-1.91) and overall CVD (relative risk (HR) 2.01, 95% CI 1.52-2.65). All studies found a positive effect, although substantial between-study heterogeneity was found for IHD and CVD. Conclusion Spontaneous preterm delivery is an independent risk factor for the development of IHD, stroke and overall CVD.