Overview of the Third Trimester of Pregnancy

MEDICAL ANIMATION TRANSCRIPT: Pregnancy is the time period during which a baby develops inside your uterus. It usually lasts about forty weeks starting from the first day of your last menstrual period. These forty weeks are grouped into roughly three segments, called trimesters. The third trimester begins about week twenty-eight and lasts until delivery. Most babies are born at around forty weeks, but some may be born before or after that time. At the beginning of the third trimester, your baby, also known as a fetus, is over a foot long from head to rump. By week thirty-two, your baby is gaining weight quickly. Your baby’s eyes can now sense light, and the eyelids open and close. The bones are still soft but fully formed. Your baby may kick and jab forcefully. At thirty-six weeks, the bones have started to harden. But the bones of the skull and the connections between them stay soft, allowing easier passage through the birth canal. Around this time, your baby will usually turn to a head-down position to prepare for birth. By the end of the third trimester, all of the organs, including the lungs, are ready to function on their own. Your baby drops lower into your pelvis and could be born any day now. You may feel more uncomfortable during the third trimester as your growing baby puts pressure on your organs. Some of the changes you may notice include shortness of breath, heartburn, swelling of your ankles, fingers, and face, tender breasts that may leak a watery pre-milk, called colostrum, your belly button sticks out, trouble sleeping, hemorrhoids, irregular, false labor pains, called Braxton Hicks contractions, and regular, true labor contractions. If you have any questions about how your baby is developing, or concerns about how you’re feeling, talk to your healthcare provider.