LAUSR

Abstract Introduction: The prenatal shunt, ductus arteriosus (DA), typically closes during the cardio-pulmonary transition at birth. We evaluated maternal and neonatal factors associated with delayed closure of DA in term-born neonates. Methods: We conducted a retrospective cohort study that included full-term neonates from the prospective observational Copenhagen Baby Heart cohort study. We assessed the association between maternal and neonatal factors and delayed ductal closure. Results: We included 19,566 neonates, of whom 48% were female. Echocardiography was performed at a median age of 12 (IQR: 9–15) and 8 (IQR: 2–13) days for neonates with no DA and an open DA, respectively. Associations with delayed ductal closure included maternal obesity adjusted risk ratio = 2 (95% CI: 1–3.8), maternal hypothyroidism during pregnancy aRR = 2.02 (95% CI: 1.2–3.4), low Apgar 2.6 (95% CI: 1.2–6), high weight aRR = 1.81 (95% CI: 1.2–2.6), and length at birth aRR = 1.7 (95% CI: 1.1–2.6). Conclusion: The identified risk factors for delayed ductal closure in term-born neonates may help increase clinical attention and improve neonatal care.