See the recommended healthy weight gain range based on your pre-pregnancy BMI and current week.
The Institute of Medicine (IOM), endorsed by the American College of Obstetricians and Gynecologists (ACOG), recommends different weight gain ranges based on pre-pregnancy BMI:
First trimester (weeks 1-12): 1-5 lbs total. Minimal gain is normal; some women lose weight due to morning sickness. Second trimester (weeks 13-26): steady gain of about 0.5-1 lb per week depending on BMI category. Third trimester (weeks 27-40): continued steady gain, though the rate may slow slightly in the final weeks.
Of a typical 30 lb pregnancy weight gain: baby accounts for 7-8 lbs, placenta 1.5 lbs, amniotic fluid 2 lbs, uterine growth 2 lbs, breast tissue 1-3 lbs, increased blood volume 3-4 lbs, body fluid 2-3 lbs, and fat/nutrient stores 6-8 lbs. Most of this weight is lost within weeks after delivery.