how much gain during pregnancy
Healthy weight (BMI of 18.5 to 24.9): If your pre-pregnancy weight was in the healthy range for your height when you conceive, you should gain between 25 and 35 pounds. For the optimal growth of your baby, aim to put on 1 to 5 pounds in the first trimester and about 1 pound per week for the rest of your pregnancy. Underweight (BMI below 18.5): If you were underweight for your height, you should gain 28 to 40 pounds.
If you start out your pregnancy over or under-weight, you will want to talk with your health care provider about what your weight gain rate should look like. 1  1-4.5 pounds during the first trimester. 2  Approximately 1-2 pounds per week in the second trimester. 3  Approximately 1-2 pounds per week in the third trimester.