The weight gain shows in the size of your belly when you're 30 Weeks pregnant! The shape of your belly changes as the belly drops due to the baby turning in a Baby Pampers New Baby with Secure-Me Fit Pregnancy Calendar Week 30 Check out what happened with your baby's development last week. is taking nutrients directly from you to build up his internal stores and to gain weight are 30 weeks pregnant. (fetal age 28 weeks). Baby measurements are 16 inches and weighs about 3 pounds. Length is 40cm and your baby's weight is 1.4 ...