Moms: Lose Weight Before Pregnancy

Obese women put their babies at risk if they don't lose weight before becoming pregnant

/ Author:  / Reviewed by: Chris Galloway, M.D.

(RxWiki News) Every parent's hope is to bring a healthy baby into the world. Women planning a pregnancy can increase those chances by first taking a good look at their own health - and their weight.

A new study reveals that even eating a healthy diet during a pregnancy can only do so much to offset the potential health risks to a baby born to an obese mother.

Developing in the unhealthy environment of an obese woman's body can increase a baby's risk of later health problems.

The best way to ensure a lower risk pregnancy and lower health risks to the baby is be at a healthy weight before becoming pregnant.

"Lose weight before becoming pregnant if you're obese."

A study led by Yuan-Xiang Pan, a nutrition professor at the University of Illinois at Urbana-Champaigne, wanted to find out if the "obesogenic environment" of an overweight pregnant mother's womb could be lessened by healthy eating.

"Obesogenic" refers to the range of unhealthy factors that conspire together to make the womb of an obese woman a less healthy environment for her developing baby.

These issues include higher levels of the hunger hormone leptin and higher levels of triglycerides, fatty molecules that can lead to thickening of the arteries.

Obese mothers have nearly twice as many triglycerides and non-esterified fatty acids, the building blocks of triglycerides which become unhealthy in large quantities.

Pan's team compared two groups of rats for their study since an experimental study of this nature on humans would be unethical.

Both groups were fed the same healthy diet during their pregnancies, but one group was obese and the rats in the other group were bred to be a normal weight.

The obese pregnant mice did not put on much weight by eating the healthy diet, said Pan, but his team found that the unhealthy factors in the womb remained for these oversized mice.

The high levels of triglycerides and fatty acids remain at unhealthy high levels even if an obese mother eats a healthy diet during her pregnancy, according to Pan.

The babies born to the obese rats were up to 17 percent smaller than they should have been, Pan said, putting them at higher risks for disease later on.

"We can see fat sequestered in the placentas of obese mothers when it should be going to the baby to support its growth," Pan said. "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."

Pan's study enabled him to show how nutrients in the placenta do not reach developing babies as effectively in obese mothers because of a specific gene that regulates the fat metabolism of the placenta.

This knowledge could help pregnant women gain a better sense of when their bodies are healthy enough to safely carry a child to term with lower health risks.

"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," Pan said.

The study appeared in the March issue of the journal Biology of Reproduction. The research was funded by the USDA Cooperative State Research, Education and Extension Service.

Reviewed by: 
Review Date: 
April 13, 2012
Last Updated:
April 14, 2012