BAKERSFIELD, Calif. -- While doctors usually say that gaining between 25 and 35 pounds during the pregnancy is healthy, researchers are reconsidering whether obese women need to gain any weight during their pregnancy.

Researchers from Kaiser Permanente followed more than 1,600 obese women during the course of their pregnancy and for one year after giving birth and found that the majority gained more than the recommended weight and the majority of these women also kept nearly half of that excess weight on for at least a year after giving birth.

Excess weight gain during pregnancy can lead to diabetes, overweight babies and birth complications, and given that more than half of women in the U.S. who become pregnant are overweight or obese, these complications are becoming far too common.

Though the latest report from the Institute of Medicine recommends that obese women should only gain about half of what is normally recommended, researchers felt that this study suggested that even a modest 10 to 15 pound weight gain isn't necessary for the mother-to-be.