Higher risk of defects for babies of obese mothers

Published on Tuesday 10 February 2009 21:08

OVERWEIGHT pregnant women are at significantly greater risk of having children with birth defects, a study has shown.

Scientists found that being clinically obese at the start of a pregnancy was associated with a wide range of congenital abnormalities.

Compared with women of normal weight, obese mothers were more than twice as likely to give birth to children with spina bifida.

The neural tube defect occurs when nerves of the spinal cord are left exposed and unprotected by the vertebrae.

The general risk of babies being born with neural tube defects, which affect the brain and spinal cord, was almost doubled for obese women.

Obesity was also associated with an increased risk of heart defects, cleft palate, hydrocephaly or "water on the brain" and reduction in limb size, according to the research reported in the Journal of the American Medical Association.

However, the British researchers pointed out that because these defects are rare to start with, even a significant increase in risk meant the chances of them occurring were still small.

An estimate of absolute risk suggested that 0.47 more births per 1,000 were likely to be affected by neural tube defects if the babies' mothers were obese during pregnancy. The same calculation for serious heart defects indicated an increase of 0.61 per 1,000 births.