Weight Gain During Pregnancy: Answers to Common Questions

Getting weighed regularly is a part of being pregnant: It’s one way that doctors track the progress of you and your baby. You can expect to step on the scale at every prenatal visit. Those appointments happen about once every four weeks for the first two trimesters, then every two weeks until 36 weeks, and finally every week until you give birth.

Weight gain during pregnancy isn’t just due to the baby growing inside you, says Tara Scott, M.D., medical director at Forum Health, in Akron, Ohio. There’s also an increase in blood volume, she says—as much as 40% by your third trimester. On top of that, Scott says, in preparation for feeding your baby, your body will store fat, and your metabolism will slow down to conserve energy.

How Much Weight Gain Should You Gain During Pregnancy?

During the first trimester, you may gain only 1 to 5 pounds, or no weight at all. After that, doctors recommend that you gain about 1/2 to 1 pound per week. The American College of Obstetricians and Gynecologists (ACOG) has guidelines for pregnancy weight gain based on your body mass index (BMI) before you were pregnant (calculate your BMI here). (Note: If you’re pregnant with twins or multiples, those numbers will be higher—if you want to know what your recommendation is, talk to your doctor.)