Parental Weight Before Pregnancy Linked to Higher Risk of Fatty Liver Disease in Adult Offspring, UK Study Finds

Key Takeaways: 

• Pre-pregnancy overweight or obesity in either parent is associated with a significantly increased risk of metabolic dysfunction associated steatotic liver disease (MASLD) in their children by early adulthood.
  
• When both parents were living with overweight or obesity prior to conception, the likelihood of MASLD in offspring by age 24 was more than three times higher.
  
• Much of this increased risk appears to be mediated by excess weight accumulated during childhood and adolescence.
  
  
  

Rising concern over MASLD across generations

Parental weight status before pregnancy may play an important role in shaping long-term liver and metabolic health in the next generation, according to new research published online in Gut. The findings suggest that overweight and obesity in both mothers and fathers prior to conception are linked to a heightened risk of metabolic dysfunction associated steatotic liver disease (MASLD) in their children as young adults.

MASLD, previously known as non-alcoholic fatty liver disease, is now recognised as the most common chronic liver condition worldwide. Researchers note that the disease affects approximately 15% of children and more than 30% of adults globally. The condition is characterised by excess fat accumulation in the liver alongside cardiometabolic abnormalities and may progress to cirrhosis or liver failure in some individuals.

While earlier studies have primarily focused on maternal obesity, uncertainty has remained regarding the contribution of paternal weight and the role of childhood weight trajectories in determining future disease risk.

Large UK birth cohort provides long-term insight

To investigate these questions, researchers analysed data from 1,933 participants enrolled in the UK Avon Longitudinal Study of Parents and Children (ALSPAC), a long-running population study tracking health outcomes across generations.

The study examined associations between parental body mass index (BMI) before pregnancy and the likelihood that offspring would develop MASLD by the age of 24.

MASLD was defined as the presence of elevated liver fat together with at least one cardiometabolic risk factor, such as raised cholesterol levels or elevated fasting glucose.

Both parents provided information on height, weight, BMI and waist circumference before pregnancy. They also completed detailed questionnaires during pregnancy and following childbirth covering a wide range of potential influencing factors, including:

• Age at delivery
  
• Smoking during early pregnancy
  
• Weekly alcohol consumption prior to pregnancy
  
• Employment status
  
• Educational attainment
  

Mothers additionally reported physical activity levels and whether they had previously been diagnosed with diabetes or hypertension at study enrolment.

Tracking early life and adolescent risk factors

Extensive information was also collected about the children, allowing researchers to examine developmental influences across childhood and adolescence. Recorded factors included:

• Sex
  
• Mode of delivery
  
• Gestational age and birthweight
  
• Antibiotic exposure during the first six months of life
  
• Duration of breastfeeding
  

Participants underwent repeated measurements of BMI and waist circumference between the ages of 7–9, 10–12 and 13–17 years. Lifestyle factors in early adulthood, including alcohol and tobacco use, were also assessed.

One in ten young adults developed MASLD

By age 24, MASLD was identified in 201 participants, representing approximately one in ten individuals in the cohort. The remaining 1,732 participants had normal liver findings.

Those living with MASLD were more likely to be male and to have a higher BMI compared with peers without the condition.

After adjusting for multiple potential confounding factors, both maternal and paternal overweight or obesity before conception were independently associated with increased odds of MASLD in offspring.

Each additional kilogram per square metre of maternal BMI increased the likelihood of MASLD by 10%, while each equivalent increase in paternal BMI was associated with a 9% rise in risk.

Most notably, offspring whose parents were both living with overweight or obesity prior to pregnancy had more than three times the odds of developing MASLD compared with those whose parents had a normal BMI.

Childhood weight plays a central role

Further analysis suggested that much of this association operates through weight gain during childhood and adolescence. Researchers estimated that 67% of the increased risk linked to parental overweight or obesity was explained by cumulative excess BMI between the ages of 7 and 17.

Additional analyses incorporating maternal and offspring sugar intake, as well as genetic susceptibility to MASLD, produced similar results, strengthening confidence in the observed associations.

Observational findings with important limitations

The authors emphasise that the study was observational and therefore cannot establish direct causation. Several limitations were also acknowledged.

Parental weight data prior to pregnancy were self-reported, and information was unavailable regarding parental MASLD status or certain underlying health conditions before and during pregnancy. In addition, physical activity levels of offspring in early adulthood were not captured, which may have influenced outcomes.

Implications for preconception health

Despite these limitations, the researchers conclude that their findings highlight the potential importance of parental metabolic health before conception in shaping long-term outcomes for future generations.

They state that the results “lend support to an early life influence of biparental obesity on offspring metabolic health, suggesting efforts to mitigate excess adiposity of both mothers and fathers before conceiving may confer longitudinal benefits to the metabolic outcomes of their future offspring.“

The study adds to growing evidence that prevention of metabolic disease may need to begin not only in childhood, but even before pregnancy, with both parents playing a meaningful role in influencing lifelong health trajectories.