Factors associated with preterm birth and low birth weight among infants with congenital heart disease in Changsha City, China, 2022–2024

This study aimed to analyze the influencing factors for preterm birth (PTB) and low birth weight (LBW) among infants with congenital heart disease (CHD) in Changsha City and to provide a scientific basis for the development of targeted preventive measures. Data on infants with CHD were collected from all the birth defects (BDs) monitoring hospitals in Changsha City from January 1, 2022 to December 31, 2024. The diagnosis of BDs was coded according to the World Health Organization's International Classification of Diseases. CHD was classified under codes Q20-Q26 in the ICD-10. Multivariable binary logistic regression was used to identify factors associated with PTB and LBW among infants with CHD. 1,460 infants with CHD were included. The overall rates of PTB and LBW among infants with CHD were 15.89% and 14.38%, respectively. Maternal folic acid supplementation was identified as a protective factor for PTB in infants with CHD (aOR = 0.40, 95%CI: 0.23-0.67), while gestational diabetes mellitus (GDM) (aOR = 3.28, 95%CI: 1.44-7.48), and comorbidity with other BDs (aOR = 1.82, 95%CI: 1.36-2.44) were identified as risk factors. Minority ethnicity was identified as a protective factor for LBW among infants with CHD (aOR = 0.35, 95%CI: 0.14-0.89), while rural residence (aOR = 1.46, 95%CI: 1.02-2.08), history of spontaneous abortion (aOR = 1.96, 95%CI: 1.33-2.87), pregnancy-induced hypertension (aOR = 3.31, 95%CI: 1.03-10.67), female sex (aOR = 1.59, 95%CI: 1.18-2.16), and comorbidity with other BDs (aOR = 2.31, 95%CI: 1.70-3.13) were identified as risk factors. The rates of PTB and LBW among infants with CHD were relatively high in Changsha City. For PTB, maternal folic acid supplementation was a protective factor, whereas GDM and comorbidity with other BDs were risk factors. For LBW, minority ethnicity was a protective factor, whereas rural residence, history of spontaneous abortion, pregnancy-induced hypertension, female sex, and comorbidity with other BDs were risk factors. Further studies are needed to elucidate the determinants of PTB and LBW among infants with CHD, with analyses stratified by specific CHD subtypes.