Week 15 - What's Going On

Week Fifteen: Bones and muscles grow

You are 15 weeks pregnant. (fetal age 13 weeks) Baby is now over 4 inches (10cm) long and weighs about 2.5 ounces (75 grams). He or she can move its arms and make a fist. Fingernails and toenails are present. Baby's skin is still very thin. Your baby's legs have grown longer than the arms and the body is now longer than the head. The bone and marrow that make up your baby's skeletal system are continuing to develop this week. The bones and muscles are continuing to grow. You may begin to feel some fluttering movements as baby kicks, twists and turns; but don't panic if you don't feel movement yet. Their ears are nearly in position, and the three tiny bones in his middle ear have begun to harden. By the end of the week, the roof of your baby's mouth will be completely formed. The fetus has an adult's taste buds and may be able to savor the mother's meals. The baby's thin skin is covered with ultra fine, downy hair that usually disappears before birth. The fetal crown to rump length by this week of pregnancy is 4 to 4.5 inches (100 to 115mm). The fetus weighs about 2.5 ounces (75g). It's close to the size of a softball.