Health risks for overweight mothers and their babies are caused by damage to egg cells and may be reversible, scientists in Australia have said.
Obese and overweight women are more likely to have fertility problems and also have an increased risk of miscarriage, while their children are more likely to suffer from birth defects, or to be obese themselves later in life.
Why this happens has not been fully understood, but in a study in mice, scientists at the University of Adelaide found that obesity leads to damage to the mitochondria – the vital energy-producing parts of cells.
All our mitochondria come from our mother. The researchers found that the eggs of obese mice produced heavier than normal foetuses, with reduced amounts of mitochondrial DNA to their offspring.
Once they had determined the cell-level chemical stresses that were causing the damage in obese mothers, researchers were able to identify compounds known to alleviate these effects. These were “highly successful” in stopping cell damage caused by obesity being passed down to offspring, they said.
The discovery holds out the possibility of a treatment that could restore “natural fertility” to obese mothers, said associate professor Rebecca Robker, lead author of the study. “It’s now well established that obesity in females leads to very serious fertility problems, including the inability to conceive. Obesity can also result in altered growth of babies during pregnancy, and it permanently programmes the metabolism of offspring, passing the damage caused by obesity from one generation to the next.
“In our laboratory studies, we’ve been able to unravel a key mechanism that leads to this multi-generational damage, and we’ve found a way to stop it happening.”
Professor Adam Balen, a leading expert in reproductive medicine at the University of Leeds, and chair of the British Fertility Society, said that while any drug treatment was a long way off, the findings were “very interesting”.
He said: “This information reinforces the need for women to be nutritionally healthy before they get pregnant.”
The findings are published in the journal Development.