Chicago ? Obese and overweight women face significantly increased risks of having babies with heart abnormalities and other birth defects, according to a government study.

Researchers from the Centers for Disease Control and Prevention said their study also confirmed an already reported link between pre-pregnancy obesity and neural tube birth defects including spina bifida.

The links between weight and other defects, including debilitating heart problems, have been less well established, the researchers said.

Compared to normal-weight women, those who were obese or overweight before pregnancy faced double the risk of having babies with heart defects and double the risk of multiple birth defects, the study said.

The study was released today in May’s editions of the journal Pediatrics.

Mothers were considered overweight if they had a body-mass index between 25 and 30, and obese if their BMI, a height-weight ratio, was 30 or higher.