Every woman has a different experience of pregnancy. According to The American College of Obstetricians and Gynecologists pregnant women should gain 25 to 35 pounds during pregnancy. The weight comes from additional changes that occur when your body is nurturing a new human being. After delivery the changes resolve as the baby expels out of body and except for few pounds all loses. Here is the breakdown of weight gain. Placenta: 1.5 pounds Maternal stores of fat, protein and other nutrients: 7 pounds Average full-term baby: 7.5 pounds Breast tissue: 2 pounds Increased fluid volume: 4 pounds Increased blood volume: 4 pounds Uterus: 2 pounds Amniotic fluid: 2 pounds Total = 30 pounds