Adriëtte Oostvogels

9 Hypothesis 3: An adverse cardiometabolic profile at age 5-6 years is the result of accelerated gain in postnatal weight, height and BMI, which is a consequence of maternal overweight before pregnancy. As expected, children of mothers with overweight or obesity before pregnancy have accelerated postnatal growth in weight, height and BMI compared to children of mothers with normal weight before pregnancy. In addition, both maternal pBMI and postnatal weight- and weight-for-length gain during the first 3 months of life were positively associated with the cardiometabolic profile of the child at age 5-6 years, as indicated by the waist-to-height ratio and the sum-score of all cardiometabolic parameters in childhood (metabolic score). Also, maternal pBMI was positively associated with offspring’s systolic/diastolic blood pressure, and postnatal weight gain was positively associated with fasting glucose values in childhood. Contrary to our expectation, however, postnatal weight- and weight-for-length gain did not mediate the associations between maternal pBMI and offspring’s cardiometabolic profile, but did independently affect offspring’s cardiometabolic profile. The most detrimental childhood outcomes were found for the combination of high maternal pBMI and accelerated weight- or weight-for-length gain. Hypothesis 4: Children from an ethnic minority population or from a lower socioeconomic background have accelerated growth patterns of overweight compared with children from European origin and/or from a higher socioeconomic background. No differences in growth patterns of overweight at age 5-6 years were found between children from European origin and non-European origin. Also, no differences were found between growth patterns of overweight between children of low- and middle-socioeconomic background. However, growth patterns of children of low socioeconomic background differed from the growth patterns observed in the high socioeconomic group. The low socioeconomic group had a lower BMI during the first 2 years. After age 3 years, BMI increased rapidly in the low socioeconomic group and at age 6 years the children with overweight in the low socioeconomic group had a higher mean BMI than those in the high socioeconomic group. Thus, the hypothesis has to be rejected for ethnic minority populations, but is confirmed for the socioeconomic groups. 221 General discussion