Pre-pregnancy weight may influence more than pregnancy outcomes. It could shape a child’s liver health decades later.
A new study published in Gut found that young adults whose parents were overweight or obese before conception had significantly higher odds of developing metabolic dysfunction associated steatotic liver disease, or MASLD, by age 24. If both parents had excess weight before pregnancy, their child’s odds of MASLD were more than 3 times higher compared with those whose parents had a normal BMI.
MASLD, formerly known as non-alcoholic fatty liver disease, is the most common chronic liver disease worldwide and is closely tied to metabolic health.
Researchers analyzed data from 1,933 participants in the Avon Longitudinal Study of Parents and Children, a long-running UK birth cohort supported by the University of Bristol and the UK Medical Research Council. By age 24, 201 participants, about 10%, met criteria for MASLD, defined as excess fat in the liver along with at least one cardiometabolic risk factor such as elevated cholesterol or high fasting glucose.
Both maternal and paternal BMI were independently associated with higher risk. Each additional unit of maternal BMI was linked to a 10% increase in the odds of MASLD. Each additional unit of paternal BMI was linked to a 9% increase.
Notably, about 67% of the association between parental overweight and offspring MASLD was explained by cumulative excess BMI between ages 7 and 17. That finding suggests much of the increased risk operated through childhood weight patterns rather than an unavoidable inherited effect.
After adjusting for mothers’ and children’s sugar intake and for genetic predisposition to MASLD, the results were similar.
The researchers wrote that the findings “lend support to an early life influence of biparental obesity on offspring metabolic health,” pointing to the possibility that improving metabolic health before conception “may confer longitudinal benefits to the metabolic outcomes of their future offspring.”
Because the study was observational, it cannot prove cause and effect. Parental weight was self-reported, and the researchers did not have complete information on parental liver disease or all adult lifestyle factors that might influence risk.
Still, the results add to growing evidence that metabolic health before conception, for both mothers and fathers, may influence long-term outcomes. The strong role of childhood BMI also highlights that early-life nutrition and growth patterns remain powerful opportunities for prevention.
This study was supported by the Washington University Pediatric Gastroenterology Research Training Program grant from the National Institute of Diabetes and Digestive and Kidney Disorders. The UK Medical Research Council and Wellcome provide core support for the Avon Longitudinal Study of Parents and Children. The specific research was funded by Wellcome Trust and Medical Research Council grants. One author reported providing consultancy services to Need and Bayer for work outside the scope of the manuscript.