Adriëtte Oostvogels

90 Chapter 3 Maternal pBMI and adiposity child (c) A higher maternal pBMI was significantly associated with a greater adiposity of the child at age 5–6 years (Table 4). The effect size of the association between pBMI and adiposity of the child decreased only slightly after adjusting for maternal lipid profile; when a reduction was apparent, this was between 0% and 2%. When all lipids were added simultaneously to the regression model, the reduction of the effect size was somewhat higher (between 0% and 20%) and there was still a significant association between maternal pBMI and adiposity of the child. This indicates that, according to the causal-steps analyses, we found no proof that maternal lipid profile mediates the association between maternal pBMI and adiposity of the child. Also when mediation was assessed by testing the mediated effect computed as the product of regression coefficient estimates, we found no convincing proof for mediation effects of the maternal lipid profile in the association between maternal pBMI and adiposity of the child. In absolute numbers the increase in pBMI from the the 2.5th percentile (18.2 kg/m 2 ) to the 97.5th percentile (32.1 kg/m 2 ) would lead to increases of offspring’s WHtR*100, fat percentage and BMI of 1.81, 2.91% and 1.39 kg/m 2 , respectively. Furthermore, a maternal pBMI of 18.2 kg/m 2 (2.5th percentile) led to an expected risk for overweight of 3.6% a pBMI of 32.1 kg/m 2 (97.5th percentile) increased this risk to 19.7%. Therefore, maternal pBMI appears to have a larger effect on the offspring’s adiposity than the maternal lipid profile. Discussion This study showed that mothers with overweight and obesity and mothers with pronounced FFA levels during early pregnancy were more likely to have children with overweight or obesity at age 5–6 years. The association between pBMI and the child’s adiposity was largely independent of the maternal lipid profile during early pregnancy. Furthermore, a significant association was present between maternal FFA and offspring’s fat percentage, BMI and risk for overweight. Also maternal ApoB and TC were positively associated with the offspring’s fat percentage and maternal TG was positively associated with their children’s WHtR, Our results are in line with others reporting a positive association between maternal pBMI and offspring’s adiposity, and between maternal pBMI and maternal lipid profile. 6,7,28,29 To our knowledge no other studies have ever explored whether an association exist between maternal lipid profile and offspring adiposity. Our observations therefore add new evidence for the existence of foetal metabolic