Maternal obesity raises the odds of birth defects

London, February 11: Adding more to the already known detrimental effects of maternal obesity, researchers of Newcastle University, United Kingdom, warn that the few extra pounds before conception could significantly increase the risk of birth defects.

To tabulate the risk of abnormalities of babies born to overweight or obese mothers, the researchers reviewed nearly 2,000 studies addressing the issue of pre-pregnancy or early pregnancy weight and birth defects. Findings of 39 studies were clubbed for the study.

Obese women were nearly twice as likely to have a baby with congenital anomalies, defects or damage to a developing fetus, than their lean counterparts.

Separately, the risk of having a baby with a neural tube defect was 87 percent; hydrocephaly (water on the brain) 68 percent; heart problems 30 percent higher for obese moms compared to normal weight women. The risk of spina bifida, incomplete closure of the neural tube resulting in an incompletely formed spinal cord, was increased more than twofold, researchers found.

While the exact cause underlining the association was not clear, the researchers floated three separate theories. Firstly, undiagnosed gestational diabetes majorly contributes to birth abnormalities. Secondly, nutritional deficiencies especially a shortfall of folic acid plays havoc for the growing fetus.

Finally, fat accumulation around the belly makes ultrasounds difficult. Thus, ultrasounds performed on overweight women are more likely to miss out on crucial defects evident early in pregnancy.

"Being obese in pregnancy can increase a woman's risk of having a range of birth defects" study’s lead author Judith Rankin wrote in Journal of the American Medical Association’s Feb.11 issue.

However fortunately, the absolute risk of an obese woman having a baby with a birth defect is still low, one in 2000 births, researchers compute. But for "women who are thinking about trying for a baby need to check their own weight first and then think about seeking help if they are overweight" Rankin recommends.

"Try to be in the best physical and emotional condition as possible before pregnancy. That means you should have excellent nutrition, you should be exercising and come in for pre-pregnancy counseling" she adds.