The pattern of your weight gain can be as important as your total weight gain during pregnancy. If you start your pregnancy at a higher BMI you will want to gain on the low end of the ranges given. If you have concerns about your weight, ask your healthcare provider for a referral to a registered dietitian to help you.
A typical pattern of weight gain (which may or may not be your experience) during pregnancy would be (1):
0-12 weeks gestation (0-3 months of pregnancy) expect 0-5 pounds (approx. 0-2.5 kilograms) of weight gain.
12-32 weeks gestation (4-7 months of pregnancy) expect between 1/2 pound to 1 pound per week (approx. 0.25-0.5 kilograms). Note: between 4-7 months a greater gain may occur because of your blood volume increasing to almost 50% over what it was before you got pregnant. (2)(3) You might gain 4-6 pounds (approx. 2-3 kilograms), instead of the usual 2-4 pounds (roughly 1-2 kilograms) at a monthly healthcare provider visit.
32-40 weeks gestation (8-9 months of pregnancy) you will often gain 1 pound (roughly 0.5 kilograms) per week because your baby is growing rapidly. Often your baby is gaining about 1 ounce per day at this point (approximately 30 grams per day). A couple of weeks before delivery weight gain can slow as your body gets ready to deliver.
- Institute of Medicine of the National Academies, Weight Gain During Pregnancy: Reexamining the Guidelines, Resource Sheet, May 2009.
- Hytten, F. Blood volume changes in normal pregnancy, Clin Haematol. 1985, Oct. 14(3): 601.
- Cilberto, CF, Marx GF, Physiological Changes Associated with Pregnancy, Available at http://e-safe-anaesthesia.org/e_library/02/Pregnancy-physiological_changes_Update_2008.pdf Accessed June 11, 2015.