Effects of suboptimal or excessive gestational weight gain on childhood overweight and abdominal adiposity: results from a retrospective cohort study

BACKGROUND: Defining prenatal modifiable risk factors of childhood overweight and obesity has become critical as the need of primary preventive strategies increases. OBJECTIVE: To investigate the interrelationship between inadequate or excessive gestational weight gain (GWG), according to maternal prepregnancy body mass index (BMI)-specific Institute of Medicine (IOM) recommendations, and childhood overweight and abdominal adiposity. DESIGN: In a retrospective cohort study in Germany, data of 6837 mother-child dyads were obtained from medical records, a questionnaire and by anthropometric measurements of children at school entry. Main exposure was GWG as categorized by the 2009 IOM guidelines and as a continuous variable. Outcome measures were children's overweight and abdominal adiposity defined as >= 90th age- and sex-specific percentiles for BMI and waist circumference, respectively. RESULTS: During pregnancy, more than half of mothers (53.6%) had gained weight excessively. Among the children (mean age: 5.8 years), 10.5% were overweight and 15.1% had abdominal adiposity. A nonlinear relationship between absolute GWG and the risk of offspring overweight and abdominal adiposity was observed. An increased risk of childhood overweight was related to excessive compared with recommended GWG, after adjustment for potential confounders (odds ratio (OR): 1.57, 95% confidence interval (CI): 1.30, 1.91), but not to inadequate GWG. Similar results were obtained for the risk of childhood abdominal adiposity by excessive GWG (OR: 1.39, 95% CI: 1.19, 1.63); there was no association with inadequate GWG. Analyses stratified by maternal prepregnancy BMI category did not suggest effect modification. CONCLUSION: Exceeding the recommended BMI-specific IOM GWG ranges has an adverse impact on the risk of childhood overweight and abdominal adiposity, whereas suboptimal GWG conveys no benefit or risk, reflecting a nonlinear relationship between absolute GWG and the risk of childhood overweight and adiposity. Strategies focussing on the awareness and prevention of excessive GWG and its consequences are justified. International Journal of Obesity (2013) 37, 505-512; doi:10.1038/ijo.2012.226; published online 29 January 2013