Pregnancy Health

Your Baby's Development

Ears move to their final position and they stand out from the head. And start brushing up on your lullabies — in the coming weeks, your baby will probably be able to hear! The bones of the middle ear and the nerve endings from the brain are developing so that your baby will hear sounds such as your heartbeat and blood moving through the umbilical cord. He or she may even be startled by loud noises!

Your baby's eyes are also developing — they're now facing forward rather than to the sides, and the retinas may be able to detect the beam of a flashlight if you hold it to your abdomen.

Until now, your baby's bones had been developing but were still soft. This week, they begin to harden, or ossify. Some of the first bones to ossify are those in the clavicles and the legs.

Pregnancy Comfort

Your Baby's Development

The senses your baby will use to learn about the world are developing daily. Taste buds have started to form on the tongue, and the brain and nerve endings are formed enough so that the fetus can feel touch. Your baby may experiment with this newfound sense of touch by stroking his or her face or sucking on a thumb, as well as feeling other body parts and seeing how they move.

Your baby's reproductive system is continuing to develop, too. In boys, the testes have begun to descend from the abdomen, and in girls, the uterus and ovaries are in place and the vagina is developed.

Yoga & Exercise

Your Baby's Development

By this first week of the third trimester, your baby looks similar to what he or she will look like at birth, except thinner and smaller. The lungs, liver, and immune system still need to fully mature, but if born now, your baby would have a very good chance of surviving.

As hearing continues to develop, your baby may start to recognize your voice as well as your partner's. Sounds may be muffled, though, because the ears are still covered with vernix, the thick waxy coating that protects the skin from becoming chapped by the amniotic fluid.

Healthy Sleep

Your Baby's Development

By now your baby is urinating approximately several cups of urine a day into the amniotic fluid. He or she is also swallowing amniotic fluid, which is completely replaced several times a day. Excess fluid in the amniotic sac (known as polyhydramnios) may mean that the baby isn't swallowing normally or that there is a gastrointestinal obstruction. Inadequate fluid in the amniotic sac (oligohydramnios) may mean that the baby isn't urinating properly and could indicate a problem with the kidneys or urinary tract. Your health care provider will measure your levels of amniotic fluid as part of your routine ultrasound.

Relax with Music

Your Baby's Development

The wrinkly, tiny fetus you may have seen on earlier ultrasounds has given way to an almost plump baby. There is fat on your baby’s cheeks, and powerful sucking muscles also contribute to your baby's full face. Your baby now weighs a little under 6 pounds (2,721 grams).

The bones that make up your baby’s skull can move relative to one another and overlap each other while your baby’s head is inside your pelvis. This phenomenon is called molding, and it helps the baby pass through the birth canal. Don't be surprised if your baby arrives with a pointy or misshapen head! After a few hours or days, your baby's head will be back to a rounded shape.

Lower Anxiety

You Baby's Development

After many weeks of anticipation and preparation, your baby is here! Or maybe not — only 5% of women deliver on their estimated due dates, and many first-time mothers find themselves waiting up to 2 weeks after their due date for their baby to arrive.

A baby born at 40 weeks weighs, on average, about 7 pounds, 4 ounces (3,300 grams) and measures about 20 inches (51 cm). Don't expect your baby to look like the Gerber baby right off the bat — newborns often have heads temporarily misshapen from the birth canal and may be covered with vernix and blood. Your baby's skin may have skin discolorations, dry patches, and rashes — these many variations are completely normal.