Impact of diabetes, obesity and hypertension on preterm birth: Population-based study

ObjectiveTo determine the impact of pre-pregnancy diabetes mellitus (D), obesity (O) and chronic hypertension (H) on preterm birth (PTB).MethodsRetrospective population-based cohort study in Ontario, Canada between 2012–2016. Women who had a singleton livebirth or stillbirth at > 20 weeks gestation were included in the cohort. Exposures of interest were D, O and H, individually, and in various combinations. The primary outcome was PTB at 241/7 to 366/7 weeks. PTB was further analyzed by spontaneous or provider-initiated, early (Results506,483 women were eligible for analysis. 30,139 pregnancies (6.0%) were complicated by PTB ConclusionCombinations of DOH significantly magnify the risk of PTB, especially provider initiated PTB, and PTB with altered fetal growth or preeclampsia.