Objectives: To investigate the prospective association between parental pre-pregnancy BMI and adult male and female offspring BMI and waist circumference (WC).Methods: Sub-sample of 2,229 parent-offspring pairs with parental pre-pregnancy BMI and offspring BMI and WC at 21 years were used from the MUSP (Mater-University of Queensland Study of Pregnancy cohort). Multivariable results were adjusted for maternal factors around pregnancy (e.g. gestational weight and smoking during pregnancy) and offspring factors in early life (e.g. birth weight) and at 14 years (e.g. sports participation and mealtime with family). Results:After adjustments for confounders, each unit increase in paternal and maternal BMI, the BMI of young adult offspring increased by 0.33kg/m 2 and 0.35kg/m 2 , and the WC increased by 0.76 cm and 0.62 cm, respectively. In the combination of parents' weight status, offspring at 21 years were six times the risk being overweight/obese (OW/OB) when both parents were OW/OB, compared to offspring of healthy weight parents. Conclusions: Prenatal parental BMI are independently related to adult offspring BMI and WC.Implications: Both prenatal paternal-maternal weight status are important determinants of offspring weight status in long-term. Further studies are warranted to investigate the underlying mechanisms.

The purpose of this study was to examine the association of parental pre-pregnancy weight and body mass index (BMI) on offspring weight and BMI change from childhood to adulthood. We analysed BMI data from a subsample of parents (n = 1494) from the Mater-University of Queensland Study of Pregnancy cohort that started in the early 1980s in Brisbane, Australia: data were collected at pre-pregnancy and then also for offspring at 5, 14 and 21-year follow-ups. Multiple regression for continuous outcomes and multinomial regression for categorical outcomes were performed. A total of 14.7% of offspring experienced BMI change from normal at 5 years to overweight or obese (OW/OB) at 14 years, 15.3% of normal at 14 years to OW/OB at 21 years and 22.8% from normal at 5 years to OW/OB at 21 years. Overall, the strength of the association of parental BMI with offspring BMI was stronger as offspring become older. Pre-pregnancy parental BMI differentially impacts offspring OW/OB across the life course. For every unit increase in paternal and maternal BMI z-score, offspring BMI z-score increased, on average, by between 0.15% (kg m ) and 0.24% (kg m ) throughout all three stages of life when both parents were OW/OB; these associations were stronger than with one parent. Parental pre-pregnancy BMI and OW/OB is a strong predictor of offspring weight and BMI change from early life to adulthood.

No abstract