Mothers who gain excessive weight during pregnancy may increase their baby’s risk of heart problems in later life, a new study suggests.
Findings from a study published in The Journal of Physiology show a baby’s heart is “programmed” by the nutrients it gets while still a foetus.
Lead study author Dr Owen Vaughan said: “Our research indicates a mechanism linking maternal obesity with cardiometabolic illness in the next generation.
“This is important because obesity is increasing rapidly in the human population and affects almost one-third of women of childbearing age,” Dr Vaughan said
The findings suggest the hearts of obese women’s unborn babies are bigger, weigh more, have thicker walls and show signs of inflammation. This impairs the organ’s ability to pump blood around the body effectively.
The study was carried out on mice by US scientists at the University of Colorado. Researchers used a mouse model that replicates human maternal physiology and the way nutrients are transported around the placenta in pregnant women.
One group of female mice were fed a fatty diet – equivalent to a human regularly eating a burger, chips and fizzy drink – until they became obese and put on one-quarter of their body weight.
Another group of mice ate a normal diet.
Mouse pups were studied in the womb after they reached three, six and nine months old and then again when they were two years old.
Researchers found that sons and daughters of obese mothers had impaired heart function, but they also noted the differences in how quickly these problems started.
For instance, males were impaired from the start while females’ cardiac function got progressively worse as they aged. The researchers say this discrepancy could be down to differences in oestrogen levels.
Higher oestrogen levels in young females may protect cardiovascular health, but this protection diminishes when oestrogen levels reduce.
The molecular cause for the difference between sexes is not yet understood, the researchers said.
If the findings in mice can be applied to humans, the discovery could pave the way for pioneering new treatments for the children of obese mothers.
“By improving our understanding of the mechanisms involved, this research paves the way for treatments that could be used in early life to prevent later-life cardiometabolic illnesses, which are costly for health services and affect many people’s quality of life,” Dr Vaughan said
Dr Vaughan added that findings from the study will also help provide tailored advice on nutrition to mothers or children based on their body mass index or sex or develop new drugs that target metabolism in the heart of the foetus.