Weight gain during pregnancy varies from woman-to-woman and depends on body type and severity of nausea and vomiting. Average weight gain for women is between 25 to 35 pounds, although slight deviations from this may also be considered normal.

Total weight gain at the end of pregnancy is, in most instances, approximated as follows, according to the March of Dimes:

• baby: 7.5 pounds
• maternal energy stores (fat, protein, and other nutrients): 7 pounds
• fluid volume: 4 pounds
• breast enlargement: 2 pounds
• uterus: 2 pounds
• amniotic fluid: 2 pounds
• placenta: 1.5 pounds

Average weight gain per trimester:

• first trimester: 3 to 4 pounds
• second trimester: 12 to 14 pounds
• third trimester: 8 to 10 pounds