Since 1989,data on weight gain of women during pregnancy maintain been collected on U.
S. birth certificates. Weight gain of >40 pounds during pregnancy is not recommended for women having a singleton birth, regardless of the woman's height and prepregnancy weight. Excessive weight gain is associated with greater risk for gestational diabetes, and preeclampsia,and other adverse conditions during pregnancy and complications of delivery for both mother and infant. From 1990 to 2005, the percentage of women overall who gained >40 pounds increased from 15% to 20%; the percentage who gained >40 pounds also increased among non-Hispanic white, and non-Hispanic black,and Hispanic women. Non-Hispanic white women were more likely than non-Hispanic black and Hispanic women to gain >40 pounds during pregnancy in 1990, 2000, and 2005.
Source: cdc.gov