Background and objectives: Preterm birth results in neonatal and childhood morbidity and mortality. Additionally, population-based studies show poorer cardiovascular health in adult survivors, but a full range of health outcomes has not been investigated into midlife. We aimed to assess the health outcomes after preterm vs term birth at 50 years in survivors of a randomized trial of antenatal betamethasone.

Methods: Participants were asked to complete a health questionnaire and for consent to access administrative data. Participants deceased prior to follow-up were assessed with administrative data alone. The primary outcome was a composite: any of diabetes mellitus, prediabetes, treated hypertension, treated dyslipidemia, or a previous major adverse cardiovascular event. Secondary outcomes included respiratory, mental health, educational, and other health outcomes.

Results: We included 470 participants: 424 assessed at mean age 49.3 years and 46 who died after infancy. The primary outcome occurred in 34.5% (112/325) of those born preterm and 29.9% (43/144) of those born at term; adjusted relative risk (aRR) 1.14 (95% CI, 0.85-1.54; P = .37). Cardiovascular events were less common in those born preterm (9/326 [2.8%] vs 10/144 [6.9%]; aRR 0.33, 95% CI, 0.14-0.79), while self-reported hypertension was more common (101/291 [34.7%] vs 23/116 [19.8%]; aRR 1.74, 95% CI, 1.16-2.61), although treated hypertension was not statistically significantly different (66/323 [20.4%] vs 22/143 [15.4%]; aRR 1.32, 95% CI, 0.84-2.06). Other components of the composite endpoint were similar between those born preterm and at term.

Conclusions: Those aged 50 years born preterm were more likely to have hypertension but had similar risk of diabetes, prediabetes, and dyslipidemia than those born at term, and their risk of cardiovascular events was lower.