Comparison of associations of maternal peri-pregnancy and paternal anthropometrics with child anthropometrics from birth through age 7 y assessed in the Danish National Birth Cohort

BACKGROUND: Maternal prepregnancy adiposity may influence child adiposity beyond the transmitted genetic effects, which, if true, may accelerate the obesity epidemic, but the evidence for this mechanism is inconsistent.

OBJECTIVE: The aim was to assess whether the associations of maternal body mass index (BMI) with child anthropometric measurements from birth through infancy and at 7 y of age exceed those of paternal associations.

DESIGN: In the Danish National Birth Cohort, information on parental and child anthropometric measures is available for 30,655 trio families from maternal interviews during pregnancy and the postpartum period and from a 7-y follow-up. By using multiple linear and logistic regression models of child SD (z) scores of weight and BMI at birth, 5 mo, 12 mo, and 7 y of age, and of child overweight at age 7 y, we compared associations with maternal prepregnancy and postpartum BMI z scores and with paternal BMI z scores.

RESULTS: When comparing maternal-child and paternal-child BMI z score associations, the strongest associations were observed with mothers' BMI at birth [maternal and paternal BMI z scores: 0.143 (95% CI: 0.130, 0.155) and 0.017 (95% CI: 0.005, 0.029), respectively] and throughout infancy, but the relative difference in the associations declined by child age [for BMI z score at child age 7 y per maternal and paternal BMI z scores: 0.208 (95% CI: 0.196, 0.220) and 0.154 (95% CI: 0.143, 0.166), respectively]. At 7 y of age, ORs of child overweight were 2.30 (95% CI: 1.99, 2.67) by maternal overweight and 1.96 (95% CI: 1.74, 2.21) by paternal overweight. There were no differences between the results based on maternal BMI before and after pregnancy or on child's weight adjusted for length or height.

CONCLUSIONS: The associations of child weight and BMI with maternal BMI were stronger than with paternal BMI. The differences between the associations were strong at birth but declined with child aging.