Weight gain during pregnancy

The recommended weight gain for a woman of normal weight is 25 lb (11.3 kg) to 35 lb (15.9 kg). A gain of 30 lb (13.6 kg) usually consists of the following:

The baby weighs 7.5 lb (3.4 kg).
The placenta weighs 1.5 lb (0.7 kg).
The amniotic fluid weighs 2 lb (0.9 kg).
The uterus weighs 2 lb (0.9 kg).
Breast tissue weighs 2 lb (0.9 kg).
Excess blood and fluids weigh 8 lb (3.6 kg).
Fat weighs 7 lb (3.2 kg).

You can expect to gain more if you are carrying twins.
If you are overweight, your ideal goal is less than the average weight gain, 15 lb (6.8 kg) to 25 lb (11.3 kg). If you are underweight, it is best to gain 28 lb (12.7 kg) to 40 lb (18.1 kg).

Ideally, you will gain weight slowly over the entire pregnancy:
0 lb (0 kg) to 4 lb (1.8 kg) during the first trimester
1 lb (0.5 kg) a week during the second and third trimesters
If you stop gaining weight for more than 2 weeks, or if you gain weight faster than these recommendations, consult your health professional