Fetal Development Week by Week – Week 15

Your baby now weighs in at about 1 ¾ ounces and is about 4 inches long.  Finally the growth of the body is catching up with the head so that they the baby doesn’t look so top heavy. 

The hair follicles begin to make pigment for dark haired babies and their bodies are completely covered with lanugo, fine hairs that protect the skin.  These hairs will disappear before birth, usually.  Hearing is becoming more sensitive and if you play music or sing your baby can hear it.  Loud noises can startle the baby at this point in time.  The heart is still pumping away, practicing for the larger volume of blood it will pump when born. 

Babies are practicing inhaling and exhaling movements.  Fingernails are completely produced and the legs are getting longer than the arms.  The skeleton is getting harder and taking in calcium quickly.  Muscles are developing, as is the very thin skin.

If you are going to have a triple test or amniocentesis this is the time frame for these tests.  Check with your health practitioner to see if either of these procedures are right for you.

Related Weeks
Fetal Development – Week 14 | Fetal Development – Week 16

Fetal Development Week by Week – Week 15