Objective: Current pregnancy weight gain guidelines are based on prepregnancy body mass indices (BMI), but gestational weight gains by BMI class among US women are unknown.
Study design: We assessed the amount of gestational weight gain among 52,988 underweight, normal-weight, overweight, and obese US women who delivered a singleton, full-term infant in 2004-2005. Excessive weight gain during pregnancy was defined as gaining 35 or more pounds for normal-weight and 25 or more pounds for overweight women.
Results: Approximately 40% of normal-weight and 60% of overweight women gained excessive weight during pregnancy. Obese women gained the least, although one-fourth of these women gained 35 or more pounds. Excessive weight gain levels were highest among women aged 19-years-old or younger and those having their first birth.
Conclusion: Excessive gestational weight gains were common, especially among the youngest and those who were nulliparous. These results predict higher obesity levels from pregnancy weight gains among US women.