Week 33: Your pregnancy

Your baby's growth: Using her senses

Your baby now weighs about 4.4 pounds and is about 16.4 inches long from head to toe. She'll gain a good deal of her weight in the final few weeks before birth.

In these last few weeks, billions of your baby's brain cells are helping her to learn about her environment. These cells help her to listen, feel and see.

This is another important week for visual development. By now your baby may be able to experience her surroundings visually, since the pupils can now detect some light. Her pupils constrict and dilate to allow your baby to see dim shapes.

Other developments this week:

• Head. Your baby's head size will increase about 3/8 of an inch in circumference this week.
• Sleep time. Your little one now sleeps much of the time.
• Lungs are continuing to mature.
• Weight gain. Fat will continue to be added on to your baby's body for protection and warmth.
• Testicles. For most boys, the testicles have now moved into the scrotum.

What's happening with you

• Head-down position. By this time the fetus should have turned around and begun to point head-down in the direction of the cervix. This will provide more space in the upper abdomen, making it easier for you to breathe.

  If you're a first-time mom, your child's head may move into the pelvis this week and press firmly against your cervix—this happens to about half of all first-time moms. If you've already had at least one child, this won't happen until about a week before labor. For some experienced moms, the baby won't move into position until the advanced stages of labor.

• Weight gain. If you're gaining a pound a week now and your weight gain ranges from 22 to 28 pounds, you're right on track. Just about half of that weight goes right to the fetus. In fact the baby gains more than half its birth weight during the next seven weeks. Be sure not to stop eating or start skipping meals as your weight increases. Both of you need the calories and nutrition of a healthy diet.
• Swelling. Although some swelling during the last trimester is completely normal, a sudden increase in swelling, combined with headaches, abdominal pain, nausea and vomiting should prompt you to contact your doctor immediately. These symptoms could be the signs of preeclampsia. Early diagnosis can help combat this complication.