- Study encompassing 2 of the world’s largest pregnancy cohorts revealed a positive association between both maternal and paternal BMI and development of childhood-onset type 1 diabetes (T1D).
- No association was observed between maternal gestational weight gain and childhood T1D.
- Findings suggest that factors influencing BMI in family, and not intrauterine mechanisms, explain association between maternal obesity and childhood T1D.
Why this matters
- Previous evidence regarding association between maternal BMI or maternal gestational weight gain and risk for development of T1D in offspring is inconclusive.
- Paternal BMI, which could clarify in utero effect of maternal pre-pregnancy, has not been evaluated previously in relation to T1D.
- 132,331 children born between February 1998 and July 2009 who participated in Norwegian Mother and Child Cohort Study and the Danish National Birth Cohort were evaluated.
- Parental BMI was categorised as underweight (<18.5), normal (18.5-24.9), overweight (25-29.9) and obese (≥30).
- Funding: None disclosed.
- Across both cohorts, maternal pre-pregnancy (aHR, 1.41; 95% CI, 1.06-1.89) and paternal (aHR, 1.51; 95% CI, 1.11-2.04) obesity were associated with an increased risk for childhood-onset T1D.
- Even after mutual adjustment, the association was similar.
- Maternal gestational weight gain throughout pregnancy was not associated with risk for childhood-onset T1D (aHR, 1.00; 95% CI, 0.99-1.02).
- Risk for selection bias.
- Parental height and weight were self-reported.