Early childhood body mass index trajectory and overweight/obesity risk differed by maternal weight status.

OBJECTIVES: To evaluate the associations of maternal prepregnancy body mass index (pp-BMI) and gestational weight gain (GWG) with the childhood BMI z-score (BMI-z) trajectories from birth to 2 years old and the risk of overweight/obesity (OWO) at 2 years of age. SUBJECTS/
METHODS: Mother-child dyads (23,617) were involved in the analysis. They were followed up from early pregnancy to 2 years postpartum with their healthcare data recorded in the Wuhan Maternal and Child Health Management Information System (WMCHMIS). The OWO in children was defined as BMI-z > 1. Linear mixed models (LMM) and unconditional logistic regression were used to evaluate the independent and joint associations of pp-BMI and GWG with the BMI-z trajectory of children per their anthropometric measurements at 0, 1, 3, 6, 9, 12, 18, and 24 months old and the risk of OWO at 2 years of age.
RESULTS: Maternal overweight/obesity and excessive GWG independently and jointly increased the risks of their offspring falling into high BMI-z trajectories of birth to 2 years (p < 0.001). In addition, the children whose mothers were overweight/obese before pregnancy and gained excessive weight during pregnancy independently and jointly increased the OWO risk in children at age 2, with adjusted odds ratios (adjOR) of 1.36 (95% CI, 1.22-1.53), 1.28 (95% CI, 1.18-1.39), and 1.76 (95% CI: 1.52-2.03), respectively.
CONCLUSIONS: Maternal prepregnancy overweight/obesity and excessive GWG can independently and jointly increase the risks of their children falling into high BMI-z trajectories from birth to 2 years of age and becoming overweight/obese at age 2. Maternal overweight/obesity and excessive gestational weight should be the prime targets for early obese prevention efforts.