The influence of maternal obesity on the long-term health of children

27 October 2016
Pregnant woman

A new paper, published this week in the Lancet, reviews the increasing evidence linking a mother’s obesity to increased health risks for her children.

The authors reviewed a range of studies looking at the possible links between maternal obesity and health outcomes in their children.

The researchers found that maternal obesity is associated with a child’s increased risk of a range of non-communicable diseases such as obesity, heart disease, stroke, asthma, and type-2 diabetes.

But they go on to say that emerging evidence suggests maternal obesity may also be linked to a child’s risk of:

  • Poorer cognition
  • Neurodevelopmental disorders, including cerebral palsy
  • Immune and infectious disease-related outcomes


The paper reviews the evidence linking maternal obesity with a number of different conditions, which are discussed below. 

Childhood obesity

The authors detail an accumulating body of evidence that now links maternal obesity and excessive gestational weight gain with increased obesity during childhood.

Furthermore, they say the evidence suggests it’s not just obese mothers, but those with a higher BMI that have children with greater adiposity and adverse body-fat distribution.

The article looks at several studies which have identified the first trimester as the most crucial in determining childhood weight gain and the risk of cardiovascular disease.

A study done of 5,000 mother–offspring pairs in the UK, showed that gestational weight gain in the first 14 weeks of pregnancy was positively associated with offspring adiposity at nine years of age. Likewise, a study among 6,000 Dutch mother–offspring dyads showed that early-pregnancy weight gain was associated with an adverse cardio-metabolic profile in childhood.

The authors say these studies suggest that maternal weight gain in early pregnancy could be a crucial period for the development of an adverse childhood cardiovascular risk profile.

“This means maternal pre-pregnancy obesity and gestational weight gain, especially in early pregnancy, could influence the risks of adiposity and adverse cardiovascular risk from childhood to adulthood,” they say.

Asthma

A mother being overweight or obese is also associated with increased asthma risk.  A meta-analysis of 14 studies and more than 100,000 mother–child pairs showed that maternal overweight or obesity in pregnancy was associated with increased risks of childhood asthma or wheeze.

The authors say maternal obesity does not appear to have any association with increased risk of eczema, sensitisation to allergens, or hay fever.

The researchers suggest that emerging evidence highlights the crucial role of the gut microbiome in the development of these disorders.

“Preliminary evidence in human beings suggests that dietary manipulation of the maternal microbiome in pregnancy with prebiotic fibre has beneficial effects for both offspring immune function and metabolism,” they say.

Immune and infectious diseases

In human beings, maternal obesity also affects the development of the baby's immune system.

“Obesity is a recognised risk factor for severe viral infections, and, in pregnant women who are obese, prenatal exposure to a range of infections (such as influenza, toxoplasmosis, rubella, cytomegalovirus infection, and herpes simplex virus infection) could have consequences for the offspring, including cardiometabolic and neurobehavioural diseases,” the authors say.

Neurocognitive and behavioural outcomes in offspring

The paper highlights data which have shown that higher pre-pregnancy weight is associated with poorer cognitive outcomes in offspring, but at the same time higher (but not excessive) weight gain during pregnancy has been associated with better cognitive outcomes.

The authors point out that maternal obesity has been associated with behavioural and emotional problems in offspring. A meta-analysis and longitudinal study showed an increased risk for autism spectrum disorders in children of mothers with obesity before or during pregnancy or with excessive gestational weight gain.

Although past studies had contradictory results relating maternal obesity to cerebral palsy in offspring, a more recent study published in 2014 showed positive associations, even after multiple adjustments.

Epigenetic modifications: a potential underlying mechanism

The paper highlights epigenetic processes as an important mechanism linking maternal adiposity and outcomes in offspring. Furthermore, the authors say evidence is now emerging that epigenetic processes can act over three or more generations and through the paternal line.

In conclusion, the authors say that increasing evidence suggests that exposure to maternal obesity leads to an increased risk of disease in offspring, but stress that more research is needed, particularly in the following areas:

  • The role of epigenetic mechanisms linking maternal obesity and long-term outcomes in offspring
  • The impact of a variety of maternal lifestyle factors on outcomes in offspring and whether these are more impactful during certain periods of development
  • The impact of intervention studies to moderate the effects of maternal obesity on offspring.

The authors say action is needed now as the prevalence of overweight and obesity in women of childbearing age increases worldwide.

You can read the full paper here.