This trimester is called the fetal stage. The third trimester is from week 29 to week 40. During this trimester, the baby's skeletons are fully formed, but still soft and fragile. During the fetal stage, babies will gain about a pound a week. By the end of the third trimester, the baby's organs are ready to function on their own. Mothers, on the other hand, go through many changes. First of all, she will have shortness of breath, swelling in her extremities, her breasts will start to leak colostrum. Also, he will have sleep problems. Additionally, you will feel contractions, which many times will be false labor