Neurons and synapses are developing in huge numbers -- forming connections in your baby's brain will give him the skills he needs to thrive as a newborn. This week, he may be able to coordinate sucking and swallowing with breathing.
While most of his bones are hardening, his skull is quite pliable and not completely joined. The bones will be able to move slightly to make birthing easier.
You baby takes intermittent deep breaths -- of water! That's okay, though since she gets oxygen from the placenta. This breathing exercises muscles and encourages her lung cells to produce more surfactant (a protein essential for healthy lung development).
If your baby is a boy, his testicles will be descending from his abdomen into his scrotum. Sometimes one or both testicles won't move into position until after birth.
Your infant is now 17.2 inches (43.7cm) long and weighs 4.23 pounds (1918gm).