Maternal dietary diversity during pregnancy and congenital heart defects: a case-control study

Maternal diet is critical to fetal development. This study aimed to explore the association between maternal dietary diversity during pregnancy and congenital heart defects (CHD) in Chinese population.

A hospital-based case-control study was conducted including 474 cases and 948 controls in Northwest China. We recruited eligible women waiting for delivery in the hospital and gathered their diets during the whole pregnancy by a validated food frequency questionnaire. According to the FAO Minimum Dietary Diversity for Women (MDD-W) guideline, the participants were categorized into "inadequate dietary diversity score (DDS)" (DDS < 5) and "adequate DDS" (DDS ≥ 5) groups. The association between dietary diversity and CHD was estimated using the mixed logistic regression models.

Case mothers had a lower DDS during pregnancy than the controls (P < 0.001). The proportions of women consuming all the ten defined food groups were lower in the inadequate DDS group than in the adequate DDS group among both cases and controls (all P < 0.001). The prevalence of inadequate micronutrient intake was higher in the inadequate DDS group than in the adequate DDS group among both cases and controls (all P < 0.05). Women in the adequate DDS group had reduced risks of having fetuses with total CHD (OR = 0.62, 95% CI = 0.45-0.84) and ventricular septal defects (OR = 0.58, 95% CI = 0.38-0.88).

Adequate DDS during pregnancy might be associated with a lower risk of CHD in offspring. Efforts to promote dietary diversity during pregnancy need to be strengthened to reduce the prevalence of CHD in Chinese population.