A new Swedish study links several adverse pregnancy outcomes to a higher long-term risk of atrial fibrillation, highlighting the importance of early cardiovascular prevention and extended follow-up for affected women. The analysis, published in JAMA Cardiology, found that all major adverse pregnancy outcomes except small for gestational age (SGA) were associated with increased risk of AF later in life.
Atrial fibrillation is a growing public health concern, affecting tens of millions worldwide. Among reproductive-aged women, the prevalence and potential long-term cardiovascular implications of adverse pregnancy outcomes have drawn increasing attention. The Swedish national cohort study aimed to clarify which outcomes influence AF risk over extended periods and how the risk evolves over time.
Study design and population
The researchers identified singleton deliveries from 1973 to 2015 using the Swedish Medical Birth Register. Women with a prior AF diagnosis were excluded. Major adverse pregnancy outcomes included preterm delivery, SGA, large for gestational age (LGA), preeclampsia, other hypertensive disorders of pregnancy, and gestational diabetes. SGA was defined as birth weight below the 10th percentile for gestational age, and LGA as above the 90th percentile.
Follow-up extended to December 31, 2018, with a maximum duration of 46 years and a median of 25 years. AF diagnoses were based on International Classification of Diseases codes, and a range of covariates were controlled, including maternal age, parity, delivery year, employment, income, and education.
Key findings
Among 2,201,047 women, about 39.3% experienced at least one major adverse outcome. The most common events were LGA (14.8%), SGA (14.3%), and preterm delivery (8.9%). AF occurred in 2.3% of participants during 54 million person-years of follow-up.
All major adverse outcomes except SGA were associated with an increased AF risk. The strongest link was with other hypertensive disorders of pregnancy, yielding a hazard ratio (HR) of 1.46. Preeclampsia followed with an HR of 1.36, then LGA (HR 1.19) and preterm delivery (HR 1.14). Gestational diabetes had an HR of 1.12.
Age at first delivery and follow-up length influenced risk patterns. Median ages were 27 at first delivery, 63 at AF diagnosis, and 53 at end of follow-up. Time-sensitive analyses showed elevated AF risk for other hypertensive disorders, preterm delivery, and LGA within 10 years of delivery (HRs 1.69, 1.46, and 1.16, respectively). Over 30–46 years, HRs for these outcomes remained elevated or modestly increased (1.44, 1.11, and 1.17, respectively).
Across the entire study period, preeclampsia and other hypertensive disorders carried substantial absolute AF risk. The largest share of AF cases occurred in the preeclampsia group (5.1%), followed by LGA (3.1%), with other adverse outcomes contributing less than 2%.
Interpretation and implications
The data indicate that five of six major adverse pregnancy outcomes are associated with an increased AF risk later in life, with the association sometimes emerging decades after delivery. SGA did not show a significant increase in AF risk.
The findings emphasize the need for early cardiovascular risk assessment and long-term surveillance for women who experience these pregnancy complications. The study suggests that AF prevention efforts should begin in the pregnancy period or soon after, and continue into midlife and beyond to identify and treat emerging cardiovascular conditions that may mediate AF risk.
Expert commentary and future directions
cardiovascular health experts stressed addressing disparities and improving long-term care for women with adverse pregnancy histories. A multi-pronged approach was recommended, including diversifying the healthcare workforce and implementing continuous support programs (such as doula services) during antepartum and postpartum periods to mitigate maternal health inequalities. The interview underscored the broader context of maternal mortality and morbidity as key drivers of long-term cardiovascular risk, calling for integrated prevention strategies that connect obstetric history with lifelong heart health.
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