[Effect of gestational weight gain on growth trajectory in children aged 0 to 3 years]

To describe the growth trajectory of body mass index for age Z score(BAZ) in children aged 0 to 3 years and to explore the association between gestational weight gain and BAZ growth trajectory.

Based on a prospective cohort study, we recruited pregnant women in their early pregnancy into this study from 2013 to 2017 in Taicang of Jiangsu Province, tracked their weight changes until they gave birth, and calculated and evaluated their gestational weight gain(GWG) as appropriate, inadequate or excessive GWG based on Chinese GWG standard. Children's height/length and weight were measured at birth, 1, 3, 6, 8, 12, 18, 24, 30 and 36 months of age, and their BAZ scores were calculated. Group-based trajectory modeling(GBTM) was used for fitting BAZ trajectories. Multilevel Logistic regression was used to analyze the association between the level of GWG and BAZ growth trajectories.

There were 1864 mother-child pairs in the study, and three groups of BAZ trajectories were fitted including slow growth trajectory(34.07%), appropriate growth trajectory(48.23%), and fast growth trajectory(17.70%). In univariate analysis, compared with children whose mothers had appropriate GWG, the children whose mothers had inadequate GWG were more likely in the group of slow growth trajectory(OR = 1.95, 95%CI 1.28-2.96), and the children whose mothers had excessive GWG were more likely in the group of fast growth trajectory(OR = 1.57, 95% CI 1.19-2.07). After adjusting for maternal pre-pregnancy body mass index(BMI) and parity, and the child's gender and birth weight, the children whose mothers gained in adequate GWG were more likely in the group of slow growth trajectory(OR = 1.84, 95%CI 1.19-2.84), while the association between excessive GWG and fast growth trajectory was not statistically significant(OR = 1.26, 95%CI 0.94-1.68).

The BAZ trajectories of children aged 0-3 years can be categorized into slow, appropriate, and fast growth groups, and children's slow growth was associated with maternal inadequate GWG.