Your baby is making breathing movements about 30-40% of the time, getting those little lungs ready for life outside of you. His bones, too, are ossifying (hardening) quickly, so be sure you’re getting enough calcium! Brain growth is rapid as well. From this week until your baby is born, about 9 weeks from now, his brain weight will double.

At week 31 of your pregnancy (about 29 weeks since conception), preparations are already being made for future generations as fetal sexual characteristics develop. If your baby is a boy, his testes are now descending through the groin, headed for the scrotum. If your baby is a girl, her clitoris is now quite visible. Important in these changes are the adrenal glands, which have doubled in size since week 22. They’re now producing large amounts of steroids, important hormones that stimulate the development and growth of sex organs, amongst other things.