Last week, vernix started to coat your baby's skin. This week, he's completely covered with the creamy substance, which will protect his delicate skin from the amniotic fluid.
Making sense. Your baby is truly starting to experience the world around him, limited though it may be. His brain has been working overtime developing the nerve centers dedicated to his senses, and they're coming alive. He's more responsive to the changes in the world around him: your activity, sounds in the environment, and even the taste of the amniotic fluid.
Pick up a hiccup. You've probably felt your baby rolling, diving, and kicking inside your belly. Now you might also feel a rhythmic jerking. No, he's not tapping out a tune; he's hiccupping. Most babies get the hiccups in utero, possibly due to an immature diaphragm having spasms. There's nothing you can do to stop the hiccups, but there's no need to—they won't harm your baby now or after he's born.
Sprouting a top. After establishing a scalp hair pattern several weeks ago, your baby is moving to the next step: growing hair. And this isn't lanugo; it's the real deal. But don't get visions of a lustrous mane just yet. Most of this hair will start to fall out two weeks after birth. Don't worry—your little one will gradually grow permanent hair, which will probably be lighter in color than the hair he has at birth. Elsewhere in your baby's head, the bones of the inner ear are now fully formed, and the nose is beginning to develop into its recognizable shape.
Measuring up. Your baby weighs about 7.5 to 9 ounces and measures approximately 8.5 inches. You could cup the little guy in the palm of your hand.
Hump week. Congratulations—you're halfway through your pregnancy! You've come a long way in four and a half months. Your uterus has grown to three times its original height. When your health care provider measures it, he or she probably will find that the top is now even with your belly button. From here on out, your uterus will grow approximately one centimeter each week until you deliver.
Womb with a view. Have you had the chance to see your baby? If you're having a mid-pregnancy ultrasound, it will probably take place between 18 and 22 weeks. Your health care provider may want to perform an ultrasound for a variety of reasons: to check your baby's growth and development, confirm your due date, screen for certain birth defects, and assess the health of the placenta and umbilical cord. Ultrasound gives you the chance to count fingers and toes, lets you find out the sex (if you want to know), and reassures you that all is well inside Hotel Mama. And, of course, this first peek at your acrobat (the one who's been keeping you awake with her antics) may make impending parenthood seem more real. Ask for a printout of the ultrasound image so you can start your baby's first picture album!
From the experts. If your life or job is high-stress, you'll be doing yourself and your baby a favor by taking measures to relax. "While certain amounts of stress are beneficial—stimulating us to take action—severe, constant stress can have negative effects on you and possibly on your baby," says Elaine Zwelling, R.N., Ph.D. Luckily, there are many ways to combat stress. Read more from Dr. Zwelling.