To investigate the joint effect of maternal pre-pregnancy body mass index (BMI) and gestational weight gain (GWG) on children’s cognitive development. We recruited 1685 mother–child pairs from the Ma’anshan Birth Cohort in China. Pre-pregnancy BMI and GWG were calculated based on the height and weights measured at multiple antenatal checkups. Children’s cognition was assessed by Wechsler Preschool and Primary Scale of Intelligence-Fourth Edition. Poisson regression model was used to analyze the association between maternal pre-pregnancy BMI and children’s cognitive dimensions under different GWG categories. Women with overweight or obese before pregnancy were more likely to obtain excessive GWG. When women had excessive GWG, pre-pregnancy overweight was associated with low children’s PSI (OR = 1.69, 95%CI: 1.02–2.81) and pre-pregnancy obesity was related to poor VCI in children (OR = 3.71, 95%CI: 1.49–9.22), after adjusting for potential confounders. In pre-pregnancy underweight mothers, adequate GWG reduced the risk of below-average VSI in children (OR = 0.22, 95%CI: 0.05–0.92), but excessive GWG was related to low FSIQ in children (OR = 2.53, 95%CI: 1.34–4.76). In women with excessive GWG, maternal pre-pregnancy BMI displays an inverted U-shape association with children’s cognition. Moreover, adequate GWG in women with pre-pregnancy underweight was beneficial for children’s cognition.

(1) Background: The aim was to examine the non-linear and sex-specific outcomes of maternal pre-pregnancy BMI on emotional and behavioral development of preschool children; (2) Methods: This study was based on the China-Anhui Birth Cohort (C-ABCS), including 3648 mother–child pairs. Maternal pre-pregnancy BMI was calculated from the maternal pre-pregnancy height and weight measured at the first antenatal checkup. Main caregivers completed the Strengths and Difficulties Questionnaire (SDQ) to assess children’s preschool emotional and behavioral development. A restricted cubic spline model was drawn using Stata version 15.1 to analyze the association between maternal pre-pregnancy BMI and preschoolers’ SDQ scores by sex; (3) Results: Among boys, maternal pre-pregnancy underweight was associated with the increased risk of conduct problems and pro-social behaviors, and pre-pregnancy overweight/obesity related with the increased risk of peer problems. Interestingly, when maternal pre-pregnancy BMI was between 18.50 kg/m2 and 18.67 kg/m2, boys had the increased risk of conduct problems. When pre-pregnancy BMI was between 18.50 kg/m2 and 19.57 kg/m2, boys had the increased risk of pro-social problems. No significant associations were observed; (4) Conclusions: A non-linear effect of maternal pre-pregnancy BMI on emotional and behavioral development has been found in preschool boys. In particular, pre-pregnancy normal weight may still affect boys’ emotional and behavioral development.

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.

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