Pregnancy Week Sixteen

Week 16 of pregnancy generally marks the end of the fourth month. You have now completed the first third of the second trimester. If you've had morning sickness, hopefully you're feeling a bit better and some of your other pregnancy symptoms have eased off too. Of course, these will be replaced by new symptoms as the pregnancy develops. Check out our information on pregnancy week 13 for a list of the symptoms which are considered normal for the fourth month.

Tests

If you're attending regular appointments with your obstetrician, as you should be, he or she will probably want to carry out the following tests by the end of the fourth month:

A check on your weight gain and blood pressure

A check on your urine to measure sugar and protein levels

Listening to your baby's heartbeat

An external exam to measure the size of your uterus

A measurement of the height of your uterus

If you are having severe symptoms or unusual symptoms, you should discuss them with your doctor (and don't feel you have to wait until your appointment if you think that something might be urgent).

Other tests may be offered from the end of the first trimester or the beginning of the second. For example, a test called a triple screen (which is optional) for Down's syndrome in your baby. Triple screen testing often provides positive results even if your baby doesn't have Down's syndrome. The test is an indicator of the likelihood of Down's syndrome, further testing would have to be carried out to confirm the results of the triple screen. Your doctor may also recommend testing for gestational diabetes, particularly if you were overweight before your pregnancy began.

Your Baby

In our page on pregnancy week 13, we described the changes that your baby goes through in the run up to week 16. Now that you've reached the end of the fourth month, your baby may even be able to make some facial expressions. He can move his limbs and may even be able to make a fist. He might even get the hiccups from time to time! You might be surprised to hear that he may be developing a thin layer of hair all over his body - this hair is called lanugo...

Lanugo Hair

Lanugo hair develops on all babies in the womb, usually in the fourth or fifth month of pregnancy. The function of the hair, which is fine and white, is to help keep your baby warm and control his body temperature. The hair grows everywhere except the genitals, the palms of the hands, the soles of the feet, the lips, the fingernails and toenails and the bits in between the fingers and toes.

The lanugo hair will stay on your baby until late in your pregnancy. In fact, some babies shed the hair only after delivery. Premature babies are sometimes born with the hair still covering their bodies. If the hair is shed inside the uterus, the baby swallows it in the amniotic fluid which surrounds him. This doesn't do him any harm at all. The lanugo hair waits in the baby's intestines and comes out in his first bowel movement after he is born.