(RxWiki News) Previous studies have shown that the amount of weight that women gain during pregnancy can significantly affect the baby's health. And it's possible that a child's health could be affected throughout childhood and beyond.
A recent study found that women who gained too little or too much weight during pregnancy had increased odds of having a child who was overweight or obese by age 2 to 5 years old. This finding was especially true for women who were a normal weight before pregnancy.
The researchers suggested that the amount of weight a mother gains during pregnancy can impact a child in ways that are independent of genetic risk factors for obesity.
"Discuss pregnancy weight gain recommendations with your OB/GYN."
The lead author of this study was Sneha B. Sridhar, MPH, from the Division of Research at Kaiser Permanente Northern California in Oakland, California.
The study included 4,145 women who completed a health survey between 2007 and 2009, and then had a single birth between 2007 and 2010 at Kaiser Permanente Northern California.
At delivery, the women were on average 33 years old. Fifty-one percent of the women were non-Hispanic white.
The researchers reviewed both the women's and the children's medical records from ages 2 to 5 years old.
Race/ethnicity, age, sex of the child, the women's pre-pregnancy body mass index (BMI; height to weight ratio), the child's birth weight, the length of pregnancy before the child was born, the women's age at delivery, the current age of the child, the women's education level, level of physical activity, whether or not the women had diabetes while pregnant and the women's dietary habits were recorded as well.
The Institute of Medicine (IOM) recommends that obese women (BMI of 30 kg/m2 or greater) should gain between 11 and 20 pounds during pregnancy, overweight women (BMI between 25 and 29 kg/m2) should gain 15 to 25 pounds, women of normal weight (BMI between 18.5 and 25 kg/m2) should gain 25 to 35 pounds and underweight women (BMI less than 18.5 kg/m2) should gain between 28 and 40 pounds.
The findings of this study showed that 11 percent of the women did not gain enough weight during pregnancy, 23 percent gained weight within the IOM recommendations and 66 percent gained too much weight during pregnancy.
Twenty percent of the children of women who gained more than the recommended weight and 20 percent of the children of women who gained less than the recommended amount were overweight or obese, compared with 15 percent of the children who were born to women who gained weight within the recommendations.
The researchers found that the women who gained less than or more than the IOM recommendations had a 46 percent and 23 percent increased risk of having a child that was overweight or obese by ages 2 to 5 years old compared to the women who gained weight within the recommendations.
The women with a normal pre-pregnancy BMI who gained less than and more than the recommended weight while they were pregnant were 80 percent and 63 percent more likely to have an overweight or obese child compared to the women who did not have a normal pre-pregnancy BMI and gained weight outside the recommended weight.
The findings suggested that the stronger association between childhood obesity and a normal pre-pregnancy BMI and gaining weight outside the weight recommendations could mean that weight gain during pregnancy could affect the child independent from genetic factors.
"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," Sridhar said in a press statement. "This could potentially have long-term effects on the child's subsequent growth and weight."
There was one study limitation due to the fact that the researchers did not have data on the women's breastfeeding habits or their children's diet after birth.
This study was published on April 14 in the American Journal of Obstetrics and Gynecology.
The Health Resources and Services Administration provided funding.