Preterm delivery increases risk of heart disease in women: JACC
Sweden: Preterm delivery increases the risk for ischemic heart disease (IHD), a recent study in the Journal of the American College of Cardiology has found. According to the study, this risk declined over time but remained substantially elevated up to 40 years later.
Preterm delivery is known to increase the future risks of cardiometabolic disorders. However, it is not clear whether preterm delivery increases the long-term risk of IHD and if such risks are due to shared familial factors. A better understanding of the risk may help in the improvement of long-term interventions and clinical follow-up for IHD prevention in women.
Casey Crump, Icahn School of Medicine at Mount Sinai, New York, New York, and colleagues determined the long-term risks of IHD in women by pregnancy duration.
The researchers conducted a national cohort study of 2,189,190 women with a singleton delivery in Sweden from 1973 to 2015. They were followed up for IHD through the end of 2015. Adjusted hazard ratios (aHRs) for IHD associated with pregnancy duration was computed using Cox regression. Cosibling analyses were used to assess the influence of shared familial (genetic and/or environmental) factors.
Key findings of the study include:
- In 47.5 million person-years of follow-up, 49,955 (2.3%) women were diagnosed with IHD. In the 10 years following delivery, the aHR for IHD associated with pre-term delivery (<37 weeks) was 2.47, and further stratified was 4.04 for extremely pre-term (22 to 27 weeks), 2.62 for very pre-term (28 to 33 weeks), 2.30 for late pre-term (34 to 36 weeks), and 1.47 for early-term (37 to 38 weeks), compared with full-term (39 to 41 weeks).
- These risks declined but remained significantly elevated after additional follow-up (pre-term vs. full-term, 10 to 19 years: aHR: 1.86;aHR: 1.52; aHR: 1.38).
- These findings did not appear attributable to shared genetic or environmental factors within families.
- Additional pre-term deliveries were associated with further increases in risk.
"In this large national cohort, pre-term delivery was a strong independent risk factor for IHD. This association waned over time but remained substantially elevated up to 40 years later. Pre-term delivery should be recognized as a risk factor for IHD in women across the life course," concluded the authors.
The study, "Pre-Term Delivery and Risk of Ischemic Heart Disease in Women," is published in the Journal of the American College of Cardiology.