The relationship between maternal oxidative balance score (OBS) in pregnancy, representing overall oxidative balance status by integrating dietary and lifestyle factors, and congenital heart defects (CHD) remains unclear; therefore, this study attempted to explore their associations among the Chinese population. We conducted a case-control study including 474 cases and 948 controls in Northwest China. Pregnant women were interviewed to report diets and lifestyles in pregnancy by structured questionnaires. Logistic regression models were used to estimate the adjusted ORs (95%CIs). Maternal OBS ranged from 6 to 34 among cases, and 5 to 37 among controls. Comparing the highest with the lowest tertile group, the adjusted OR for CHD was 0.31 (0.19–0.50). The CHD risk was reduced by 7% (OR = 0.93, 95%CI = 0.90–0.95) in association with per 1 higher score of OBS during pregnancy. The inverse relationship between maternal OBS and CHD risk appeared to be more pronounced among participants in urban areas (OR = 0.89, 95%CI = 0.86–0.93). Maternal OBS during pregnancy showed good predictive values for fetal CHD, with the areas under the receiver operating characteristic curve 0.78 (0.76–0.81). These findings highlighted the importance of reducing oxidative stress through antioxidant-rich diets and healthy lifestyles among pregnant women to prevent fetal CHD.

Background/Objectives: The impact of choline on congenital heart defects (CHDs) in humans remains unclear. This study aimed to investigate the associations between maternal dietary intakes of choline and choline derivatives during pregnancy and CHD. Methods: This case–control study included 474 cases and 948 controls from hospitals in Northwest China. Pregnant women admitted for delivery were enrolled and completed a validated food frequency questionnaire to assess their dietary intake during pregnancy. A standardized questionnaire was also administered to collect additional pregnancy-related information. Mixed logistic regression models were used to estimate ORs (95%CIs) for CHD in association with choline intake. Results: Higher intakes of total choline, phosphatidylcholine, sphingomyelin, glycerophosphocholine, and phosphocholine in pregnancy were associated with reduced risks of total CHD, ventricular septal defects, and atrial septal defects, with all trend tests showing statistical significance (all p < 0.05). The ORs (95%CIs) of total CHD, comparing the highest with the lowest tertiles of intake, were 0.38 (0.24–0.61) for total choline, 0.51 (0.38–0.70) for phosphatidylcholine, 0.37 (0.26–0.51) for sphingomyelin, 0.34 (0.21–0.53) for glycerophosphocholine, and 0.53 (0.34–0.82) for phosphocholine. The inverse associations remained unchanged according to maternal age, work, education, parity, passive smoking, anemia, medication use, or folate/iron supplements use in pregnancy; however, these associations appeared to be more pronounced among pregnant women in urban areas. Conclusions: Higher maternal intake of dietary choline during pregnancy may be associated with a lower risk of CHD. Promoting choline intake in pregnant women could serve as a potential strategy for the primary prevention of fetal CHD in China.