Preterm Birth Linked to Higher Mortality in Adulthood

TOPLINE:

Individuals born preterm face an increased risk for death from all causes even into their third and fourth decades of life.

METHODOLOGY:

• Researchers conducted a population-based study in Canada, analyzing data from 4.99 million births that occurred between January 1983 and December 1996, with follow-up through December 2019.
• The researchers compared preterm births (24-37 weeks gestation) with term births (37-41 weeks), breaking down preterm births into subcategories of 24-27 weeks, 28-31 weeks, 32-33 weeks, and 34-36 weeks.
• The analysis attempted to account for factors including sex of the child, multiple births, birth province, birth year, parents’ ages, maternal marital status, maternal parity, and parental birth origins.

TAKEAWAY:

• Over a median follow-up of 29 years, 72,662 people in the study died, including 14,312 who had been born preterm and 58,350 born at term.
• The highest risk difference in the rate of death (2.29%; 95% CI, 2.23%-2.35%) and risk ratio ([RR], 11.61; 95% CI, 11.09-12.15) were observed in birth through infancy.
• Mortality in early childhood (ages 1-5 years) was elevated among preemies (risk difference, 0.34%; 95% CI, 0.31%-0.36% and RR, 2.79; 95% CI, 2.61-2.98).
• Increased mortality was associated with respiratory, circulatory, and digestive system disorders. The highest risk was found in conditions that start during the perinatal period (hazard ratio, 37.50).
• Compared with individuals born at term, prematurity was associated with elevated risk differences for death linked to several health conditions, including respiratory problems (2.4), digestive issues (1.7), and nervous system diseases (4.1).
• The increased mortality risk associated with prematurity declined over the study period but appeared to tick higher in the last decade (RR, 1.30 for all-cause mortality among people aged 29-36 years).

IN PRACTICE:

“The findings of this cohort study suggest that individuals born preterm were at increased risk of death from birth to their third and fourth decades of life, and the risks were higher with decreasing GA at birth,” the study authors wrote. “Some of these associations may have been partly due to underlying health determinants that affected both PTB and mortality. These findings suggest that [preterm birth] should be recognized as a risk factor for mortality and could inform preventive strategies. Additionally, they highlight the need for further follow-up studies to assess possible adverse consequences of [preterm birth] into adulthood.

SOURCE:

The study was led by Asma M. Ahmed, PhD, MD, MPH, of the Department of Epidemiology and Prevention at Wake Forest University School of Medicine in Winston-Salem, North Carolina. It was published online on November 20, 2024, in JAMA Network Open.

LIMITATIONS:

The study relied on physician- or parent-reported data on gestational age, which may be subject to measurement errors. Including births from the 1980s and 1990s may limit generalizability to recent births due to advances in perinatal care. The researchers lacked information on maternal health and comorbidities, type of preterm birth, presence of congenital malformations, and maternal socioeconomic and lifestyle factors.

DISCLOSURES:

The research was supported by grant 438541 from the Canadian Institutes of Health Research and Statistics Canada.

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