The most dramatic development this week: reflexes. Your baby's fingers will soon begin to open and close. His or her mouth will make sucking movements. Toes will curl, and eye muscles will clench. Meanwhile, nerve cells are multiplying rapidly, and in your baby's brain, synapses are forming furiously.
In fact, if you prod your abdomen, your baby will squirm in response, although you won't be able to feel it. Your baby's intestines, which have grown so fast that they protrude into the umbilical cord, will start to move into the abdominal cavity, and the kidneys will begin excreting urine into your baby's bladder.
Your baby's face looks unquestionably human: His or her eyes have moved from the sides to the front of the head, and the ears are right where they should be. From crown to rump, your baby-to-be is just over 2 inches long (about the size of a lime) and weighs half an ounce.