Pregnancy Weight Gain by Kimberly A. Tessmer, R.D., L.D.

The health and weight of your baby at birth depend greatly on how much weight you gain over the course of your pregnancy. The weight of your baby factors into your weight gain, but your body also gains weight through its increase in blood volume — about 50 percent — as well as muscle, fluid, and tissue. Your body weight increases at a different rate depending on your stage of pregnancy. During the first trimester, weight gain is slow, about 2 to 4 pounds. During the last six months, weight gain should increase to about ½ to 1 pound per week, depending on your total target weight gain. Even though all women differ slightly, it is best to gain weight at a steady pace.