The Baby at 30 Weeks

Week 30: Making Headway

Your baby's height and weight haven't changed much in the past week, but the big news is your baby's brain gain. Until now, the surface of your baby's brain was smooth. Now, your fetus's brain is taking on those characteristic grooves and indentations. The reason for this change in appearance? Those wrinkles allow for an increased amount of brain tissue — a necessary change as your baby prepares for life outside your womb, and the street smarts he or she will need.

Another big change this week: Your baby's bone marrow has taken over production of red blood cells (before, tissue groups and then the spleen took care of producing the blood cells). This is an important step for your baby, because it means he or she is better able to thrive on his or her own once born (with a little TLC from you, of course).

So it's in with the new (brain cells, red blood cells) and out with the old (lanugo). Much of the lanugo — the soft, downy hair covering your baby's body — is beginning to disappear now because both fat and the brain are regulating your baby's body temperature (so no need for that furry coat anymore). But you may see a few leftover strands of fur on your newborn's back and shoulders.