Adverse birth outcomes linked to heightened risk of AF up to middle age

Individuals who were born preterm and large for gestational age (LGA) are at increased risk of atrial fibrillation (AF) up to middle age, and the risk increase is independent of familial confounding factors, according to a multinational cohort study.

For the study, researchers used data from Danish, Swedish, and Finnish national health registries. They identified live singleton births in Denmark from 1978 through 2016, in Sweden from 1973 through 2014, and in Finland from 1987 through 2014. AF diagnoses were obtained from nationwide inpatient and outpatient registers.

A total of 8,012,433 adults (maximum age 49 years, median age 21 years, 51.3 percent men) comprised the study population. Over 174.4 million person-years of follow-up, 11,464 adults (0.14 percent) received an AF diagnosis at a median age of 29.3 years.

Multivariable Cox proportional hazard models showed that both preterm birth (<37 gestational weeks) and LGA (>90th percentile birth weight for gestational age) were associated with increased AF risk in both the full population cohort and in the sibling analyses.

The corresponding hazard ratios for AF from the cohort analyses were 1.30 (95 percent confidence interval [CI], 1.18–1.42) with preterm birth and 1.55 (95 percent CI, 1.46–1.63) with LGA.

Of note, preterm birth showed a stronger association with AF in childhood than in adulthood. Meanwhile, individuals born small for gestational age (<10th percentile birth weight for gestational age) were at increased risk of AF in the first 18 years of life but not afterwards.