New research finds that obesity in pregnancy impairs heart health and function of the foetus in a mice study.
Obesity in pregnancy can lead to many possible complications for the woman and her baby, including miscarriage, blood clots, gestational diabetes and pre-eclampsia. However, new research highlights the effects of obesity in pregnancy on the offspring.
Researchers from the University of Colorado discovered that obesity in pregnancy causes molecular changes in the heart of the foetus and alters the expression of genes related to nutrient metabolism, which greatly increases the offspring’s risk of cardiac problems in later life.
Studying the impact of obesity in pregnancy
To replicate human maternal physiology and placental nutrient transport in women who are obese in pregnancy, the researchers used a mouse model. Female mice were fed a diet with high-fat content and a sugary drink until they reached obesity and another group of mice were fed a control diet.
Mouse pups were studied in utero and after birth at three, six, nine and 24 months using imaging techniques, including echocardiography and positron emission tomography (PET) scans. Researchers analysed the genes, proteins, and mitochondria of the offspring.
Changings in cardiac metabolism
The gender of the mouse pups strongly determined the changes in offspring cardiac metabolism. The expression of 841 genes was altered in the hearts of female foetuses and 764 genes were altered in male foetuses, but less than 10% of genes were commonly altered in both sexes.
Although both male and female offspring from pregnant obese mice had impaired cardiac function, there were differences in the progression between sexes; males were impaired from the start, whereas females’ cardiac function got progressively worse with age.
The sex difference in the lasting impairments of cardiovascular health and function could be due to oestrogen. The high levels of oestrogen in young females may protect cardiovascular health; the protection diminishes as oestrogen levels deplete as the females’ age. However, the researchers noted that the molecular cause for the sex difference is not yet understood.
Lead author, Dr Owen Vaughan, University of Colorado, US, 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. 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. For example, we could offer more 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.”