Month by Month

Week by week changes to expect in the fifth month of pregnancy

Baby’s Growth

Week 18

Two exciting things happen around this week: your baby may be developed enough to see and to hear. Your baby uses these skills before she is born as a way to familiarize herself with the environment she will live in. Although her eyes are only able to detect the difference between bright light and darkness, this helps her learn about the day/night schedule where you live.

The sounds she hears are muffled because of the amniotic fluid, but she does hear enough to become familiar with the voice of her mother and others who live in her home. She may also become familiar with the type of music you listen to.

Week 19

Your baby has been developing two forms of protection for his skin; lanugo hair and vernix caseosa. The vernix is a thick and creamy white substance that prevents the amniotic fluid from damaging the skin. It slowly wears off near the end of your pregnancy, so babies born early tend to have more on their skin than babies born late. Lanugo hair develops all over the body and seems to help the vernix remain attached to the skin. The lanugo will also fall off near the end of your pregnancy.

Week 20

Her skin is developing the layers it needs to provide protection to the bones, muscles and other tissues underneath. This thickening process will make her skin opaque (you will not be able to see through it any more).At the end of the 20th week your baby will be around 7.5 inches from crown to rump and weigh 1 pound, and baby’s kidney’s are now functioning well enough that they can make urine.

Week 21

As the bones are hardening, the bone marrow is also developing. It is now developing the ability to produce blood cells (this is the function of marrow in an adult). Until the marrow can do this on its own, your baby’s liver and spleen are making his blood.

To Do List

  1. You should continue to eat well and exercise to stay as healthy as possible. Eating a good quality diet is important to your health and hers.

  2. You will need to start looking into your options for childbirth classes about half way through the second trimester. Although you may not be thinking about labor yet, it will happen. It can take time to weigh your options and find all the resources available in your community. You can look for local classes in the Natural Childbirth Directory.
  3. You may want to start thinking how your new baby is going to fit into your home. There is a wide variety of baby equipment available, and you certainly don’t need it all. Consider your lifestyle, the flow of your home and your frequent travels. What equipment well be the most useful, what equipment will just get in the way. Many families find baby equipment acquired because the idea sounded good or because everyone else had one, just sat in a closet and was given away because baby outgrew it without having used it. If this is not your first child, consider how much of the equipment you used the first time will still serve your family well, and what things you didn’t have will now make sense to buy.
Jennifer (Author)