A recent report warns women of childbearing age to pay more attention to their weight before they become pregnant in order to have a healthy baby.
In the study, scientists compared the placentas of obese rats and obesity-resistant rats. All were fed a healthy diet throughout their pregnancies. Results showed that despite not gaining much weight, the “obesogenic” environment already established inside the overweight mothers remained and caused unhealthy effects on the foetus.
Offspring were up to 17 percent smaller than they should have been and, according to the authors, this was due to changes on the surface of the placenta which influenced nutrient transport to the baby.
“We can see fat sequestered in the placentas of obese mothers when it should be going to the baby to support its growth,” said co-author Dr Yuan-Xiang Pan from the Department of Food Science and Human Nutrition at the University of Illinois. “The nutrient supply region in the placenta of an obese mother is half the size of that of a normal-weight mother, even when both are eating the same healthy diet.”
Obesity during pregnancy is now a common condition affecting approximately one in five pregnant women. Reporting in the Journal Biology of Reproduction, the authors analysed placentas for fat accumulation and expression of the DKK1 gene, a protein involved in embryonic development. By monitoring the levels of DKK1, scientists were also able to demonstrate, for the first time, that DKK1 controls certain aspects of lipid metabolism in the placenta. They hope monitoring the protein could provide markers for healthy pregnancy.
“Obesity creates unhealthful conditions in the mother’s body that take time to correct,” said Dr Pan. “Understanding this process should help us identify some biomarkers that would allow a potential mother’s doctor to say ‘yes, you’ve lost weight, the chemical conditions that were created by your excess weight are gone, and this is a good time for you to become pregnant’.”
This report adds to the body of knowledge from previous studies into the health risks posed by maternal obesity, both for the mother and child during and after pregnancy.
For instance, according to a 2001 study from Imperial College, maternal obesity carries significant risks for the mother and foetus, likely to be related to the altered metabolic state associated with morbid obesity.
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