Women who gain too much or too little weight during their pregnancy are more likely to have an overweight child, according to a recent study.

Researchers found that women with a normal body mass index (BMI) measurement before pregnancy who gained less than the recommended amount were 63 percent more likely to have a child who became overweight or obese. They also found that women with a normal BMI before pregnancy with weight gain above recommendations were 80 percent more likely to have an overweight or obese child.

"The stronger association we found among normal weight women who gained too much or too little weight during pregnancy suggests that perhaps weight gain in pregnancy may have an impact on the child that is independent of genetic factors," senior investigator Monique M. Hedderson of the Kaiser Permanente Division of Research in Oakland, Calif., said in a statement.

For the study, researchers reviewed the electronic health records of 4,145 racially diverse female members of Kaiser Permanente in Northern California who had completed a health survey between 2007 and 2009 and subsequently had a baby. Researchers then analyzed the medical records of those children between ages 2 and 5 years old.

Investigators also found that among all women who gained more than the recommended weight during pregnancy, 20.4 percent of their children were overweight or obese, compared with 19.5 percent in women who gained less than recommended weight and 14.5 percent in women who gained weight within the guidelines.

"Gaining either too little or too much weight in pregnancy may permanently affect mechanisms that manage energy balance and metabolism in the offspring, such as appetite control and energy expenditure," Sneha Sridhar, the study's lead author, said in a statement, "This could potentially have long-term effects on the child's subsequent growth and weight."

Starting BMI guidelines and weight gain recommendations used in the study are from the Institute of Medicine. For obese women (BMI of 30 or greater), the recommended weight gain during pregnancy is 11 to 20 pounds; for overweight women (BMI between 25 and 29), it is 15 to 25 pounds; for normal weight women (BMI between 18.5 and 25), it is 25 to 35 pounds; and for underweight women (BMI less than 18.5), it is 28 to 40 pounds.

The findings were recently published in the American Journal of Obstetrics and Gynecology.