Baby Lack-Update 2

Week 17-Your baby's skeleton is changing from soft cartilage to bone, and the umbilical cord — her lifeline to the placenta — is growing stronger and thicker. Your baby weighs 5 ounces now (about as much as a turnip), and she's around 5 inches long from head to bottom. She can move her joints, and her sweat glands are starting to develop.

Week 18-Head to rump, your baby is about 5 1/2 inches long (about the length of a bell pepper) and he weighs almost 7 ounces. He's busy flexing his arms and legs — movements that you'll start noticing more and more in the weeks ahead. His blood vessels are visible through his thin skin, and his ears are now in their final position, although they're still standing out from his head a bit. A protective covering of myelin is beginning to form around his nerves, a process that will continue for a year after he's born. If you're having a girl, her uterus and fallopian tubes are formed and in place. If you're having a boy, his genitals are noticeable now, but he may hide them from you during an ultrasound.

Week 19-Your baby's sensory development is exploding! Her brain is designating specialized areas for smell, taste, hearing, vision, and touch. Some research suggests that she may be able to hear your voice now, so don't be shy about reading aloud, talking to her, or singing a happy tune if the mood strikes you.Your baby weighs about 8 1/2 ounces and measures 6 inches, head to bottom — about the size of a large heirloom tomato. Her arms and legs are in the right proportions to each other and the rest of her body now. Her kidneys continue to make urine and the hair on her scalp is sprouting. A waxy protective coating called the vernix caseosa is forming on her skin to prevent it from pickling in the amniotic fluid.