Women with adverse pregnancy outcomes have a higher long-term risk of developing atrial fibrillation (AF) according to researchers, and there is thus the need for early preventative measures and long-term follow-up. A recent research established that with the exception of small for gestational age babies, all other significant pregnancy complications such as preterm birth, preeclampsia, gestational diabetes, large for gestational age babies, and other hypertensive disorders were linked with increased AF risk up to 46 years later, regardless of common familial influences. The study was published inJAMA Cardiologyby Casey C. and colleagues. Complications during pregnancy have been associated with increased cardiovascular risk in later life for decades. Yet, information on their direct association with AF, an increasingly prevalent cardiac arrhythmia significantly raising the stroke and heart failure risk, is still limited. A better appreciation of these risks will help high-risk women be identified at an early stage to prompt preventive interventions that would minimize the burden of AF and its complications. This Swedish national cohort study recruited all women in Sweden who had a singleton birth between 1973 and 2015, for a total of 2,201,047 participants, with 54 million person-years of follow-up. Six principal adverse pregnancy outcomes were investigated by researchers using national birth records: preterm birth, small for gestational age, large for gestational age, preeclampsia, other hypertensive disorders, and gestational diabetes. AF diagnoses were ascertained via inpatient and outpatient records through 2018. Cox regression models estimated hazard ratios (HRs) for AF while adjusting for maternal covariates. Cosibling analyses were performed to determine whether confounding by common genetic and environmental factors existed. Of the study cohort, 51,173 women (2.3%) were diagnosed with AF with a median age at diagnosis of 63 years (IQR 56-69). Within 10 years post-delivery: Other hypertensive disorders: HR 1.69 (95% CI, 1.32-2.15) Preterm delivery: HR 1.46 (95% CI, 1.26-1.70) Large for gestational age: HR 1.16 (95% CI, 1.01-1.32) 30 to 46 years after delivery: Other hypertensive disorders: HR 1.44 (95% CI, 1.24-1.66) Preeclampsia: HR 1.38 (95% CI, 1.33-1.50) Gestational diabetes: HR 1.19 (95% CI, 1.03-1.37) Large for gestational age: HR 1.17 (95% CI, 1.14-1.21) Preterm delivery: HR 1.11 (95% CI, 1.07-1.16) Women with multiple adverse pregnancy outcomes also had increased AF risk. Cosibling analyses indicated these associations were very largely independent of common familial factors, providing evidence of a potential causal association between pregnancy complications and subsequent AF development. All the pregnancy complications excluding small for gestational age were linked with a raised risk of atrial fibrillation up to 46 years later in this big national cohort. Early preventive measures and long-term clinical follow-up are needed in such pregnancy-complicated women to identify and treat cardiovascular disorders related to AF.