Adriëtte Oostvogels

Abstract Background: Maternal prepregnancy overweight is known to program offspring for adverse health outcomes later in life. Aims: To investigate how growth patterns of weight, height and BMI from birth to 7 years differ according to maternal prepregnancy weight (normal weight, overweight and obesity), with specific attention for sex differences. Study design: Prospective multi-ethnic ABCD-study. Subjects: 3805 mother-child pairs were included. Self-reported maternal prepregnancy body mass index (BMI) was categorized into: normal weight (18.5-25 kg/m 2 ; n=3354), overweight (25-30 kg/m 2 ; n=711) and obesity (≥30 kg/ m 2 ; n=241). Outcome measures: Population-specific growth patterns were used to compute SD-scores for weight, height and BMI (on average 12.7 (SD=2.6) measurements for each child) for term born boys and girls separately. Mixed effect models were fitted to these SD-scores to determine the effect of prepregnancy BMI category on postnatal growth, corrected for maternal characteristics. Results: Compared to children of mothers with normal weight before pregnancy, children of overweight mothers grew faster in weight and BMI (boys and girls) and children of obese mothers grew faster in height (only girls), weight and BMI (boys and girls) during the first years of life. The differences seemed to increase with age and were in general larger in girls. Conclusion: Maternal overweight and obesity impact on offspring’s weight, height and BMI growth pattern with increasing differences when children age. Effects were in general stronger for girls. These results suggest that a healthy weight before pregnancy may be beneficial for optimal weight, height and BMI growth in the offspring. 148 Chapter 6