Building bone strength
Your baby’s bones are soaking up lots of calcium as they harden, so be sure to drink your milk (or find another good source of calcium, such as cheese, yogurt, or enriched orange juice). About 250 milligrams of calcium are deposited in your baby’s skeleton each day.
The respiratory sacs at the tips of your baby’s lung branches have begun making a substance called surfactant, which keeps them inflated when there’s not a lot of air in the lungs (when exhaling, for example). While her lungs are still immature, they would be capable of functioning – with a lot of medical help – if she were to be born now.