Crown to rump, your baby is between 4 and 4 1/2 inches long, and weighs 1 3/4 ounces. The body is now growing faster than the head. This week, its parchment-thin skin covers itself with lanugo (ultra-fine, downy hair that usually disappears before birth). Though eyebrows are beginning to grow and the hair atop the head is sprouting, this hair may change in both texture and color after birth. About now, the fetus can grasp, squint, frown, and grimace. It may even be able to suck its thumb. Researchers believe these and other movements probably correspond to the development of impulses in the brain.
If you haven't yet scheduled a triple-screen maternal serum (a type of blood test), you may want to do so now. The test provides more information about your baby, and screens for Down syndrome and other birth defects. Also, healthcare providers may recommend an amniocentesis between 15 and 18 weeks for women over 35 and those with a history of birth defects.
