Babies born to obese women face a very high risk of suffering an oxygen deficit at birth compared to those born to average-weight women. Researchers have reached the conclusion after conducting a study that examined data from the Swedish medical birth registry for all 1.7 million births that occurred in the country between 1992 and 2010.

Apgar score, a measure of oxygen deficit at birth, was found to be lower for kids born to obese women. The risk of low Apgar score for kids born to overweight women (with a BMI of 25 to 29.9) was 55% higher at five minutes after birth compared to babies born to normal-weight women. On the other hand, kids born to obese mothers (with a BMI of 30 to 39) faced a twofold increase in risk and babies born to very obese women (with a BMI of 40 or higher) had a more than threefold increase in risk.

The results clearly indicated that obesity is not a health risk for the person itself, but pregnant mothers who are obese also increase the chances of oxygen-deficit for their kid at birth, said study author Dr. Martina Persson, of the Swedish medical university Karolinska Institutet.

The findings supported the previous studies that suggested increased risks for maternal, fetal and neonatal complications because of maternal overweight and obesity.

Women who want to plan family must make efforts to attain a normal body weight before conception. A link between a pregnant woman's obesity and other delivery complications has also been showed by a previous research.

The researchers said the latest study did not provide them any evidence to prove that that a woman's BMI has the potential to put the baby at a risk of birth asphyxia. "In our analyses, we found that mode of delivery, whether a baby was delivered vaginally or by Cesarean section, did not substantially affect the risks of birth asphyxia in offspring of overweight and obese women", Persson added.