Peri-Conceptional Folic Acid Supplementation and Children’s Physical Development: A Birth Cohort Study

Background: Maternal lack of folic acid supplementation during pregnancy may increase the risk of low birth weight and preterm delivery. However, little is known about the relationship between folic acid supplementation during pregnancy and the physical development of offspring in the later stage. Objective: This study aimed to explore the association between maternal folic acid supplementation status during pregnancy and the physical development of preschool children. Methods: A total of 3064 mother–child pairs with data on maternal folic acid supplementation status during pregnancy and children’s anthropometric measurements were recruited from the Ma’anshan-Anhui Birth Cohort (MABC) in China. Maternal folic acid supplementation status during pregnancy was the main exposure, and the primary outcomes were children’s growth development trajectories. Children’s growth development trajectories were fitted using group-based trajectory models. The association between maternal folic acid supplementation status during pregnancy and children’s growth trajectories was performed using multiple logistic regression models. Results: After adjusting for potential confounders, we found that the absence of maternal folic acid supplementation before pregnancy and in the first trimester was significantly associated with a “high level” trajectory (trajectory 3) and a “high rising level” trajectory (trajectory 4) of BMI-Z scores in children 0 to 6 years of age (OR = 1.423, 95%CI:1.022–1.982; OR = 1.654, 95%CI: 1.024–2.671). In children aged 4 to 6 years old, a “high level” trajectory (trajectory 3) of body fat ratio was substantially related to maternal no folic acid supplementation before pregnancy and in the first trimester (OR = 1.833, 95%CI:1.037–3.240). No significant additional benefits associated with physical developmental indicators in preschool children have been observed with continued folic acid supplementation after the first trimester of gestation. Conclusions: Maternal non-supplementation with folic acid during pregnancy is associated with a “high level” BMI trajectory and a “high level” body fat ratio trajectory in preschool-aged children.