Varies. With each woman. Don't expect anything. Most women gain about 20 pounds. Some less, some more. Your doctor will help you if he/she thinks you are gaining too much. A healthy baby is the goal and gaining some weight is important.
Pregnancy weight gain. The general recommendation for weight gain during pregnancy ranges from 25 to 35 pounds. However, it is acceptable for underweight women to gain more and for overweight women to gain less. A well balanced diet with about 2200 to 2900 calories each day - depending on the weight of the woman - is the appropriate caloric intake for most pregnant women.
Average is 25-35 lbs. But if you gain less and your baby is growing normally that is fine, I never worry about low weight gain in my pts., as long as the baby is growing normally. Many pts have trouble with too much wt gain. And at your age do not go past your due date, new studies show ideal time to deliver is 39-40 weeks. Too many things can happen that could have been avoided when u go past your due date!
2009 IOM guidelines. Here are the 2009 institute of medicine guidelines for pregnancy weight gain, based on a woman's bmi (body mass index) before becoming pregnant with one baby: underweight: gain 28-40 pounds normal weight: gain 25-35 pounds overweight: gain 15-25 pounds obese: gain 11-20 pounds.