Adverse childhood experiences and pre-pregnancy body mass index in the HUNT study: A population-based cohort study

OBJECTIVE: Investigate the association between adverse childhood experiences and pre-pregnancy body mass index (BMI) in a population-based cohort in Trøndelag county, Norway. MATERIALS AND METHODS: We linked data from the third (2006–2008) or fourth (2017–2019) survey of the Trøndelag Health Study (HUNT) and the Medical Birth Registry of Norway for 6679 women. Multiple logistic regression models were used to examine the association between adverse childhood experiences and pre-pregnancy BMI. Adverse childhood experiences were self-reported in adulthood and included perceiving childhood as difficult, parental divorce, parental death, dysfunctional family environment, bad childhood memories and lack of support from a trusted adult. Pre-pregnancy BMI was derived from the Medical Birth Registry of Norway or BMI measurement from the HUNT survey conducted within 2 years prior to the woman’s pregnancy. RESULTS: Perceiving childhood as difficult was associated with higher odds of pre-pregnancy underweight (OR 1.78, 95%CI 0.99–3.22) and obesity (OR 1.58, 95%CI 1.14–2.2). A difficult childhood was positively associated with obesity with an adjusted OR of 1.19, 95%CI 0.79–1.81 (class I obesity), 2.32, 95%CI 1.35–4.01 (class II obesity) and 4.62, 95%CI 2.0–10.65 (class III obesity). Parental divorce was positively associated obesity (OR 1.34, 95%CI 1.10–1.63). Bad childhood memories were associated with both overweight (OR 1.34, 95%CI 1.01–1.79) and obesity (OR 1.63, 95%CI 1.13–2.34). Parental death was not associated with pre-pregnancy BMI. CONCLUSIONS: Childhood adversities were associated with pre-pregnancy BMI. Our results suggest that the positive associations between childhood adversities and pre-pregnancy obesity increased with increasing obesity level.