Associations of maternal gestational weight gain with the risk of offspring obesity and body mass index Z scores beyond the mean

Purpose: We examined the association of meeting the 2009 Institute of Medicine gestational weight gain (GWG) guidelines with offspring obesity and body mass index Z score (BMIZ) at age six overall and by maternal weight status. Methods: Data were from the Infant Feeding Practices Survey II Study (2005–2007) and their Year Six Follow-Up Study (2012). Logistic regression and quantile regression models were used. Results: Eleven percent of children were obese. Children born to mothers who gained excessive weight during pregnancy had an increased risk of obesity as compared with those born to mothers who gained adequate weight (adjusted odds ratio: 1.67). The association was stronger among normal-weight mothers (adjusted odds ratio: 3.50). Inadequate GWG was not associated with offspring obesity overall or in subsamples by maternal prepregnancy BMI. Children born to mothers who gained excessive weight had higher BMIZ. This distributional association was more pronounced among normal-weight mothers. Children born to obese mothers who gained inadequate weight had lower BMIZ at some percentiles of the BMIZ distribution. Conclusions: Excessive GWG was associated with increased risk of offspring obesity and higher BMIZ at age six, whereas inadequate GWG was protective of high BMIZ among children born to obese mothers.