On average, a healthy amount of weight gain during pregnancy is 25-35 pounds (11.3-15.9 kilograms) for normal weight women. This is usually reached by gaining 1-4 pounds (0.4 to 1.8 kilograms) during the first trimester, and about 2-4 pounds (.9-1.8 kilograms) each month from 4 months until delivery.

Where does this weight come from? According to the Nemours Foundation, this is how a 30 pound (13.6 kilogram) pregnancy weight gain is typically distributed:

  • 7.5 pounds (3.4 kilograms): your baby’s weight
  • 1.5 pounds (.6 kilograms): the placenta
  • 2 pounds (.9 kilograms): enlargement of your uterus
  • 2 pounds (.9 kilograms): amniotic fluid surrounding your baby
  • 2 pounds (.9 kilograms): breast enlargement
  • 4 pounds (1.8 kilograms): your extra blood
  • 7 pounds (3.17 kilograms): your extra stored nutrients
  • 4 pounds (1.8 kilograms): your extra body fluids

Pregnant Woman

Pregnant Woman With Fetus
© Nucleus Medical Media, Inc.

Keep in mind that pregnancy weight gain may vary.

  • If you are underweight, you should gain 28-40 pounds (12.7-18.14 kilograms).
  • If you are overweight, you should gain 15-25 pounds (6.8-11.33 kilograms).
  • If you are obese, you should gain 11-20 pounds (4.9-9.07 kilograms).
  • If you are having multiples (twins, triplets), you will gain more weight, so talk to your doctor about the amount of weight gain that will be best for you.

If you gain too much weight during pregnancy, you will be at increased risk of complications, including diabetes, high blood pressure, constipation, and back pain. In addition, your labor and delivery may be longer and more difficult. You may also be at increased risk of needing a cesarean section.

If you gain too much weight during pregnancy, your baby may also be at risk for being stillborn or having congenital abnormalities at birth. Babies born to obese mothers are also at risk for obesity and heart disease later in life.

If you don’t gain enough weight, your baby will not get the nutrients needed to grow and develop properly.