Week Thirty One: Baby detects light
You are 31 weeks pregnant. (fetal age 29 weeks)
- Baby weighs 3.5 pounds and measures 16.5 inches from the head to heel.
- Baby’s weight is about 1.6 kg and length around 42cm.
- The eyes have now completely opened and are responding to light and darkness.
- A loud noise near you may cause your little one to jump.
Your baby continues to grow. Baby’s lungs and digestive tract are very near to being mature. Now that almost all of the major organs are functioning, growth will focus on maturing those organs and growing muscle mass and fat stores. Baby’s weight gain will exceed its growth in length from now on. He or she should more than double their weight again between now and birth. It weighs about 3.5 pounds (1.6kg), and crown to rump length is 11 inches (28cm). Its total length is 16.5 inches (42cm).
A loud noise near you may cause your little one to jump. Baby may move to the rhythm of music. Studies with heart rates show that they may also prefer some types of music to others at this stage. The eyes can now completely open and the irises are now responsive to light, dilating and contracting as needed.
You will probably find that though you have been feeling pretty energetic throughout your second trimester, you are beginning to slow down now. Pay attention to your body’s signals and rest when you need to. Exercise is still an important activity for you, even though it gets harder as you get larger and heavier. Try swimming, stretching and walking all excellent options for pregnant women.
Your total pregnancy weight gain by this time should be between 21 and 28 pounds (9.5 and 12.5kg).
Your baby’s lungs are fully developed this week, although they’re not mature yet. He’ll be “breathing” rhythmically now, though, although occasionally he will swallow some down the wrong way and get hiccups, which you can feel.
He’s gaining weight rapidly as he lays down fat in preparation for his big arrival, and the brain connections that control sensory input are forming now. His bones are fully developed (although still soft) and he’ll begin building up his own stores of iron and calcium. This is all the more reason to ensure you are getting enough of these minerals in your diet, to keep your own stores topped up.
It’s possible your baby will turn into a head down position in preparation for birth, although some babies leave it until the very last minute so don’t be too concerned if he hasn’t shown signs of doing so yet. Your doctor can usually tell where your baby is lying by palpating (feeling) your bump.
This week, your baby measures over 16 inches long. He weighs about 3.3 pounds (try carrying four navel oranges) and is heading into a growth spurt. He can turn his head from side to side, and his arms, legs, and body are beginning to plump out as needed fat accumulates underneath his skin. He’s probably moving a lot, too, so you may have trouble sleeping because your baby’s kicks and somersaults keep you up. Take comfort: All this moving is a sign that your baby is active and healthy.
Baby’s now the size of a squash!
Baby’s going through major brain and nerve development these days. His irises now react to light, and all five senses are in working order. (He won’t pick up anything from his nose until after birth, though — smell is transferred through air, not amniotic fluid.)