A new study published in The Journal of Physiology found that obesity during pregnancy causes molecular changes in fetus’s hearts that increase their risk of cardiovascular issues later in life.
The researchers used mice to model human pregnancy and study the effects of an unhealthy diet and obesity on their offspring. They fed 31 female mice a diet high in sugar and fat that caused obesity, comparable to a human diet high in unhealthy intake like sugary sodas and fried foods. As a control, 50 female mice were fed a standard mouse diet. The mice in the experimental group developed obesity and gained approximately 25% of their body weight before becoming pregnant.
The mice in the study had 187 offspring (called pups), and a variety of measurements were taken at 3, 6, 9, and 24 months after their birth. Both female and male offspring showed altered gene expression when their mothers were obese, but the changes depended strongly on sex. Both sexes had impaired cardiac function due to the differences in gene expression, but the males were impaired throughout the measurements, while the females became more impaired with age.
The lead author of the study noted that this work indicates a mechanism linking maternal obesity to cardiac impairments in offspring. Obesity is a widespread and worsening issue around the world, and almost one out of three women of childbearing age is affected by obesity. This research may help optimize nutritional and weight-related goals for pregnant women, and it could also be used to develop drugs that improve heart health in fetuses or young children of mothers with obesity.