Gaining too much weight during pregnancy can bring serious health consequences.
Almost half of US women who carried a pregnancy of a single child to full term last year gained more weight than recommended, according to data released today by the CDC.
Gestational weight gain was above guidelines from the Institute of Medicine (IOM) for 48% of this group, while 32% gained the recommended amount of weight and 21% gained too little, the data show.
Those most likely to gain too much weight were already overweight (61%) or obese (55%) before they became pregnant. Among women who were normal weight (body mass index (BMI) = 18.5 to 24.9), 39% gained weight within recommended guidelines, while 44% of those who were underweight (BMI <18.5) gained the recommended amount of weight.
The CDC defines being overweight as having a BMI of 25 kg/m2 or higher, and one is obese when BMI reaches 30 kg/m2.
The 2015 data continue recent trends; a study published last year cited CDC data that around 47% of women gained more weight than IOM guidelines.
Getting pregnant while obese, and then gaining too much weight during pregnancy, can bring significant health consequences. Obesity has long been known to be a risk factor for gestational diabetes, which can be harmful to both mother and baby.
A 2015 study published in The American Journal of Clinical Nutrition found that excessive weight gain during pregnancy can cause women to put on pounds that are never lost. Women who were not overweight before pregnancy, but had other risk factors for obesity, and then gained too much gestational weight, seemed to be particularly sensitive to its harmful effects, the researchers found.
IOM guidelines on how much weight women should gain vary depending on how much they weigh when pregnancy begins. Normal-weight women should gain about 25 to 35 pounds, while overweight women (BMI = 25 to 29.9) should gain 15 to 25 pounds. Women who are obese should gain 11 to 20 pounds, while those who are underweight should gain 28 to 40 pounds.
QuickStats: Gestational weight gain among women with full-term, singleton births, compared with recommendations—48 states and the District of Columbia, 2015. MMWR Morb Mortal Wkly Rep. 2016;65:1121. DOI: http://dx.doi.org/10.15585/mmwr.mm6540a10