Cardiovascular Impact After Preterm Birth

TOPLINE:

Adults aged 50 years who were born preterm have a higher risk for hypertension but lower risk for cardiovascular events than those born at term, with similar risks for diabetes, prediabetes, and dyslipidemia between groups.

METHODOLOGY:

• The researchers conducted a prospective cohort study of the Auckland Steroid Trial — the first randomized trial of antenatal corticosteroids (betamethasone) for women who were at risk for preterm birth, conducted in Auckland, New Zealand, between December 1969 and February 1974.
• They analyzed 470 participants, including 424 survivors recruited between January 2020 and May 2022 and 46 participants who died after infancy.
• The outcomes for 326 participants born preterm (mean age, 49.4 years) and 144 participants born at term (mean age, 49.2 years) were assessed using either a questionnaire, administrative datasets, or both.
• The primary outcome was a composite of cardiovascular events or risk factors, defined as a history of a major adverse cardiovascular event or the presence of at least one cardiovascular risk factor, including diabetes mellitus, prediabetes, treated dyslipidemia, and treated hypertension.
• The secondary outcomes included respiratory, mental health, educational, and other health outcomes, as well as components of the primary outcomes.

TAKEAWAY:

• The composite of cardiovascular events or risk factors occurred in 34.5% of participants born preterm and 29.9% of participants born at term, with no differences in the risk factor components.
• The risk for cardiovascular events was lower in participants born preterm than in those born at term (adjusted relative risk [aRR], 0.33; P =.013).
• The participants born preterm had a higher risk for high blood pressure (aRR, 1.74; P = .007) and the composite of treated hypertension or self-reported diagnosis of high blood pressure (aRR, 1.63; P =.010) than those born at term.
• From randomization to the 50-year follow-up, death from any cause was more common in those born preterm than in those born at term (aRR, 2.29; P<.0001 whereas="" the="" diagnosis="" or="" treatment="" of="" a="" mental="" health="" disorder="" was="" less="" common="">P =.007); no differences were observed between the groups for other outcomes.

IN PRACTICE:

“Those aware of being born preterm also may be more likely to seek preventive treatments, potentially resulting in a reduced risk of cardiovascular disease but a greater prevalence of risk factors if defined by a treatment such as treated dyslipidemia or treated hypertension,” the authors wrote. “In this cohort, the survival advantage of the term-born control group abated after infancy, with a higher all-cause mortality rate compared with that of the group born preterm,” wrote Jonathan S. Litt, MD, MPH, ScD, and Henning Tiemeier, MD, PhD, in a related commentary.

SOURCE:

The study was led by Anthony G. B. Walters, MBChB, Liggins Institute, Auckland, New Zealand. It was published online on December 16, 2024, in Pediatrics. The commentary by Litt, Department of Pediatrics, Stanford University School of Medicine, Palo Alto, California; and Tiemeier, Department of Social and Behavioral Sciences, Harvard T.H. Chan School of Public Health, Boston, was also published online in Pediatrics.

LIMITATIONS:

The small sample size limited the ability to detect subtle differences between groups and the validity of subgroup analyses. Attrition bias may have occurred due to low follow-up rates among presumed survivors. Missing data from the participants in the questionnaire or due to lack of consent for access to the administrative dataset could have introduced bias. The lack of in-person assessments for blood pressure and blood tests, resulting from geographical dispersion over 50 years, may have led to underestimation of some outcomes. Additionally, as most participants were born moderately or late preterm, with a median gestational age of 34.1 weeks, findings may not be generalizable to those born preterm at earlier gestational ages.

DISCLOSURES:

The study was supported in part by the Aotearoa Foundation, the Auckland Medical Research Foundation, Cure Kids New Zealand, and the Health Research Council of New Zealand. The authors of both the study and the commentary reported no conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.