Adriëtte Oostvogels

4 105 Maternal lipids and offspring’s lipids & glucose Offspring’s lipid profile and glycaemic control At the health check at age 5-6 years, TG (mmol/L), TC (mmol/L), high density lipoprotein (HDL) (mmol/L), LDL (mmol/L), glucose (mmol/L) and C-peptide (nmol/L) were determined based on fasting capillary blood samples collected with an ambulatory collection kit (Demecal: Lab Anywhere, Haarlem, the Netherlands). Details on these analyses are reported elsewhere. 16 Because of the detection limit of C-peptide from >0.34 nmol/L, 63.6% of the C-peptide levels were missing. Therefore, sex, age and body mass index of the children were used to predict the missing concentrations (below the detection limit of 0.34 nmol/L) with survival analyses. This analysis was conducted in R package applying a log-logistic distribution because it was most fitting, based on log likelihood. Glucose and C-peptide concentrations were used to quantify insulin resistance with the homeostatic model assessment (HOMA2-IR). Offspring’s fat percentage During the health check at age 5-6 years, body fat percentage was measured by arm-to-leg bioelectrical impedance analysis (Bodystat 1500 MDD machine; Bodystat Inc., Douglas, UK). For this analysis, calculations based on equations adapted from Lohman et al. and Kushner et al. were used. 17 Covariates Maternal age (years; continuous), pBMI (kg/m 2 ; continuous), smoking behaviour during pregnancy (yes/no), alcohol intake during pregnancy (yes/no), education level (years after primary school; continuous) and ethnicity (Dutch, Turkish, Moroccan, other Western and other non-Western) were obtained from the pregnancy questionnaire. Ethnicity was defined by the country of birth of the mother of the pregnant woman. Information on maternal hypertension [none/pre-existent hypertension/gestational hypertension, based on the International Society for the Study of Hypertension in Pregnancy guidelines (www.isshp.com) ] was obtained by combining records of the Dutch perinatal register (PRN) and the pregnancy questionnaire. Parity (primiparous/multiparous) and sex of the child were available from the Youth Health Care Registration. Data on the duration of exclusive breastfeeding (no breastfeeding, <1 month, 1-3 months, > 3 months) was obtained from the infancy questionnaire 3 months after birth and Youth Health Care records and completed with, retrospectively, the 5-year questionnaire. The following variables with regard to offspring at age 5-6 years were included: screen time hours a day (continuous), saturated fat intake (g/day; continuous) and dietary fibre intake (g/day; continuous).