The big job in the third trimester is to put on weight and prepare for birth. The baby’s movements become more and more restricted as the months go by and the space in the womb becomes more crowded. Your baby will gain most of its weight during the last two months and will get into a head down position in preparation for birth. The trimester ends when your baby is born at the end of the ninth month.
The Seventh Month:
Your baby is now longer than your uterus and curls up in a fetal position. By the end of this month, the baby weighs three pounds and is about eleven inches long. The body is growing faster and the baby is putting on weight rapidly this month. The hands make grasping motions. The lanugo hair on baby’s body begins to fall out. Hair on the head continues to grow.
The eyelids have been fused shut until now, but will open this month. The baby blinks and eyelashes are growing. Although the uterus is dark, your baby will begin to sense changes in light and darkness, particularly when you are outside on a bright, sunny day. The taste buds are forming and baby can now sense differences in sweet and sour tastes. The brain begins to separate into ridges and grows larger this month. The different areas of the brain begin to take on their intended function, the jobs they will have throughout your child’s life.
The Eighth Month:
The fetus is preparing to live outside the womb this month. The brain and nervous system continue to mature, but won’t be completely matured until after birth. The arms and legs become more plump. Babies don’t really breathe in the womb, but do make breathing movements in preparation for breathing on his own after birth. If he is a boy, his testicles will drop from his body this month.
The baby’s immune system is preparing for life outside the womb as well. Antibodies from your blood pass through the placenta to the baby to help her resist illness after birth, until her own immune system becomes strong enough to take over the job. If your baby were born this month, he or she would survive in the vast majority of the cases.
The Ninth Month:
This month ends with the birth of your baby. The baby is fully developed and is mostly gaining weight this month. The baby will gain about a half ounce per day throughout this month. The vernix begins to come off the baby’s skin. In most cases, your baby will get into position for birth. This is usually head down and facing your back. The head may begin to descend into the pelvis a week or two before birth. This is known as lightening. Although it can be an indication that birth is close, no one really knows when labor will begin. The trimester ends when labor starts and you welcome your newborn into the world.