A recent study conducted on 40,000 mothers and their babies found that 1-in-5 women gain too much weight during pregnancy, which doubles the chances of their babies gaining 9-pounds or more.

The findings of the research by Dr. Hillier M.D., of Kaiser Permanente Northwest and colleagues have been published  in the November issue of Obstetrics and Gynecology.

The research also found these babies are prone to obesity later in life.

"The take-home message is that all pregnant women need to watch their weight gain and it is especially important for women who have risk factors like gestational diabetes," said Dr Hiller

"Because a recent study found that one-third of women reported receiving no provider advice on gestational weight gain, our findings emphasize the need for both advising and monitoring women to avoid excessive weight gain," the researchers said.

The researchers also pointed out that low gestational weight gain can have equally adverse pregnancy outcomes, so "our results should be interpreted with the perspective that the goal is ideal weight gain."

According to the findings of the researchers, women who had gestational diabetes and gained more than 40 pounds were at the highest risk. The risk is 29% versus 13.5% of women who had gestational diabetes and gained a healthy amount of weight.