Babies Born Preterm or Large Have an Increased Risk of Afib in Adulthood

Adverse birth outcomes were linked to a child's increased risk of atrial fibrillation (Afib) developing later in life or in adulthood, a population-based study showed.

Based on more than 8 million individuals from three Nordic countries, preterm birth (adjusted hazard ratio [aHR] 1.30, 95% CI 1.18-1.42) and large for gestational age (LGA) birth (aHR 1.55, 95% CI 1.46-1.63) were associated with increased Afib risk by a median age of 29 years, reported Fen Yang, MD, MSc, of the Karolinska Institute in Stockholm, and colleagues.

Sibling analyses controlling for unmeasured familial confounders supported these results and also found that small for gestational age (SGA) birth was associated with an increased risk of Afib caught during childhood (aHR 1.27, 95% CI 1.07-1.50) but not during adulthood (aHR 0.90, 95% CI 0.84-0.96), the researchers detailed in JAMA Pediatrics.

If these findings are confirmed by further studies, "early lifestyle-related counseling and effective preventive measures may be implemented among survivors of preterm birth or with abnormal birth size to reduce their risk of developing atrial fibrillation in later life," according to Yang and co-author Krisztina László, PhD, also of the Karolinska Institute, in a joint statement to MedPage Today.

Pediatric electrophysiologist Aarti Dalal, DO, of Vanderbilt University Medical Center in Nashville, Tennessee, agreed that having information about adverse birth outcomes could be potentially helpful for patients in the future.

"If we can begin to identify non-modifiable personal risk factors such as birth weight or prematurity, then these personal details that most of us currently do not have [a] need to remember could potentially be used when counseling a patient about their future risk of atrial fibrillation," said Dalal, who was not involved with the study.

"At a time when we have increased access to personal and biometric health data, knowing your history may continue to prove to be vital in predicting your future risks," she added in her email to MedPage Today.

Preterm birth and low birth weight still accounted for about 16% of infant deaths in 2020, according to the CDC. However, survivors of adverse birth conditions have been increasing in number due to major advances in neonatal care over the past decades.

"Increasing evidence shows that these survivors have higher risks of obesity, diabetes, or certain cardiovascular diseases later in life," Yang and László noted. Afib in young patients "could entail a heavy socioeconomic burden, but knowledge on its etiology is very limited."

For their study, the investigators looked at prospectively recorded nationwide data from Danish, Swedish, and Finnish national health registries. Live singleton births in Denmark were included from 1978 through 2016, in Sweden from 1973 to 2014, and in Finland from 1987 to 2014.

Median age was 21 years and 51.3% were males. Of this cohort, 4.7% were born preterm, 10.0% SGA, 10.0% LGA, and the remaining appropriate for gestational age (AGA).

During follow-up, 0.14% (n=11,464) of the 8,012,433 total participants received a diagnosis of Afib at a median age of 29.3 years, the researchers reported.

Considering both gestational age and birth weight for gestational age, compared with term AGA births, the risk of Afib was increased by 71% in preterm LGA births, 55% in term LGA births, 31% in preterm AGA births, and 25% in preterm SGA births. The risk of Afib was 9% lower for term SGA than term AGA births.

Limitations of the study included that some asymptomatic, paroxysmal, or mild cases of Afib may have been missed due to their reliance on national records, Yang and colleagues noted. Additionally, though the study's sibling analysis could partly control for unmeasured familial risk factors, the design still leaves room for bias.

Furthermore, the study's findings apply only to children and young adults and cannot be generalized to the predominant group of individuals developing Afib at an older age. And results may only be generalized to countries with predominantly white populations and universal free healthcare systems, they added.

"Further studies with longer follow-up and that may elucidate the underlying mechanisms for the observed associations are warranted," the study authors wrote. "As the prevalence of LGA births is reported to increase over time, the possible long-term health effects of being born LGA may become increasingly important."

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