Obesity Increases Birth Defect Risk
Heart, Spine, and Limb Defects Seen More
Twofold Rise in Spina Bifida continued...
A slightly lower increase in risk was identified for omphaleocele, a condition in which the intestines or another abdominal organ protrudes through the navel.
Obesity-related risk increases in the range of 20% to 50% were also seen for heart defects, limb abnormalities, malformations in the anal opening or urethra in boys, and a condition known as diaphragmatic hernia, which can interfere with lung development.
The study is published in the August issue of the Archives of Pediatric and Adolescent Medicine.
Diabetes and Birth Defects
Having uncontrolled or poorly controlled diabetes prior to conception or early in pregnancy has been linked to an increased risk for major birth defects in both animal and human studies.
While women with known, nongestational diabetes were excluded from the latest study, it is likely that some of the obese women had type 2 diabetes and didn’t know it.
Waller says undiagnosed diabetes could be largely responsible for the increase in birth defect risk seen among babies born to obese women in the study.
When the researchers reanalyzed the data excluding women who developed gestational diabetes during pregnancy, the maternal obesity-birth defect link was much smaller, she says, but it did not disappear entirely.
"Obese women need to follow the same recommendations as other women prior to becoming pregnant," she says. "But it would also be a good idea for them to see their doctor and get tested for diabetes. We know that many women have diabetes and don't know it. Identifying diabetes and controlling it prior to pregnancy can make a big difference."
March of Dimes acting director Michael Katz, MD, calls the study intriguing, but he adds that more research is needed to confirm the link between obesity and major birth defects.
"No matter what a woman’s weight, it is important to plan a pregnancy," he tells WebMD. "Planning ahead and taking steps to reduce modifiable risks can make all the difference."