Your Baby in the Third Trimester of Pregnancy
Fetal growth continues in the last trimester, especially brain growth. It's important to continue to eat nutritious foods.
- By the seventh month (the beginning of the third trimester), your baby will be able to open and close her eyes, suck her thumb, and cry. You will feel her kicking. As the baby continues to grow and fill the uterus, the amniotic fluid begins to decrease. By the end of this month, your baby will weigh about three pounds and be about 15 inches long.
- During the eighth month, your baby grows about another three inches and adds about two more pounds. She may kick hard because she’s larger and taking up more room. You may see rhythmic movements of your belly, caused by the baby hiccupping or sucking her thumb. Your baby's brain is growing rapidly, but the bones in her head are still soft to make it easier for her to fit through the birth canal. During this month, she may jump suddenly if she becomes startled. She cannot breathe on her own yet because her lungs are still forming.
- By the end of the ninth month, your baby's lungs will be fully mature and she is ready to breathe on her own. During this month, she will gain about half a pound every week, to reach a birth weight of approximately seven pounds. She will also add a few more inches to her height, and will be about 18 to 21 inches long at birth. To get ready for her trip through the birth canal, the baby will begin to move downward (this is called "lightening"), so that her head rests deep in your pelvis. This usually happens two to six weeks before labor, unless you have had a baby before, in which case it may not occur until you go into labor.
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Childbirth Connection is a national not-for-profit organization founded in 1918 as Maternity Center Association. Our mission is to improve the quality of maternity care through research, education, advocacy and policy. Childbirth Connection promotes safe, effective and satisfying evidence-based maternity care and is a voice for the needs and interests of childbearing families.
Most recent page update: 9/9/2010