Analyses of more than 2 million patients found that preterm and early births were associated with an increased risk of ischemic heart disease.
After examining more than 2 million patients with up to 43 years of medical records, investigators found that those born preterm and early-term had higher incidence rates of IHD than full term births.
Investigators from the Icahn School of Medicine at Mount Sinai used the Swedish Birth Registry to identify 2,242,967 singleton live births in Sweden from 1973 to 1994. Due to inclusion criteria, a total of 2,141,709 (95.5%) were included within the study.
The population was categorized into 5 groups based on gestational age at birth. The groups were defined as early preterm (less than 34 weeks), late preterm (34 to 36 weeks), early term (37 to 38 weeks), full term (39 to 41 weeks), and postterm (42 weeks or more). The full term group was used as the reference group.
Investigators followed up for the earliest diagnosis, per ICD codes, for IHD through 2015. Additionally, Cox proportional hazards regressions were used to compute hazard ratios and 95% confidence intervals for associations between gestational age at birth and incident IHD between the ages of 18 and 43.
Upon analyses, which took place in Sept. 2018, 1921 persons (6.21 per 100,000) had received a diagnosis of IHD. Conversely, the incidence rate among those born preterm was 8.79 and 6.48 among those categorized as early term. The rate among full term births was 5.85 per 100,000.
Between the ages of 30 and 43, low gestational age at birth was more strongly associated with risk of IHD compared with earlier in adulthood (18 to 29 years old). In adjusted analyses, they found preterm and early term birth were associated with a 53% (95% CI, 20% to 94%) and 19% (95% CI, 1% to 40%) increased relative risk of new-onset IHD in the older age group.
Authors noted that women born preterm had lower incidence of IHD than mean (15.16 versus 22 per 100,000) but had a higher adjusted hazard ratio (1.93; 95% CI, 1.28-2.90 versus 1.37; 95% CI, 1.01-1.84). In their discussion authors wrote that this could be caused by lower baseline incidence among women born full term.
Within their conclusion, the study authors wrote that their findings suggest preterm and early term birth are risk factors for development of IHD. Additionally, they feel that persons born prematurely need long-term follow-up and early preventive actions to reduce the risk of developing IHD.
In a related commentary published on JAMA Pediatrics, Adrien Flahault, MD, PHD, and colleagues at CHU Sainte-Justine in Canada wrote that the study highlights the need to treat adults born preterm as an at-risk population for cardiovascular disease — even if not recognized as an indication for screening by the American Heart Association or American Diabetes Association.
“Physicians caring for adults should routinely inquire about birth history to identify this at-risk population. Raising awareness among individuals born preterm and their families is equally important to promote healthy lifestyle habits and encourage protective behavioral changes,” Flahault et al. wrote.
This study, titled “Association of Preterm Birth With Risk of Ischemic Heart Disease in Adulthood,” was published in JAMA Pediatrics.