From pregnancy to breastfeeding: adequate maternal body mass index is essential to prevent a high body mass index in your children

Objectives To verify the associations between prenatal and perinatal factors with offspring body mass index (BMI) and the moderator role of maternal BMI in this relationship. Methods Cross-sectional study developed with 1,562 children and adolescents aged between 6 and 17 years, as well as their mothers, from southern Brazil. The prenatal and perinatal factors, weight, and height for the calculation of maternal BMI were self-reported. For the calculation of BMI, weight and height of the child/adolescent were measured on an anthropometric scale with a coupled stadiometer. Linear regression models were used for the moderation analysis. All analyzes were adjusted for the mother’s and child’s age, sex, sexual maturation, skin color/race, and educational level. Results cesarean as type of delivery (β=0.66; 95% CI=0.22 1.04; p=0.002) and pregnancy complications (β=0.60; 95% CI=0.15 1.04; p=0.002) were positively associated with offspring BMI. Schoolchildren who were breastfed for 4–6 months showed −0.56 kg/m2 of BMI (95% CI=−1.06–0.06; p=0.02). Birth weight was also associated with BMI, with low weight being inversely (β=−0.59; 95% CI=−1.03–0.15; p=0.008), while overweight was positively related (β=0.84; 95% CI=0.08 1.60; p=0.02). The moderation analysis indicated a positive interaction between the mother’s BMI and cesarean, pregnancy complications, and smoking with the offspring’s BMI. On the other hand, there was an inverse association between breastfeeding from 7 to 12 months and the offspring BMI, only in mothers with high BMI. Conclusions Adequate maternal BMI is essential to prevent a high BMI in their children, especially when considering the influence of prenatal and perinatal risk factors.