week 12 (What To Expect When Expecting)

By now, your baby weighs a full half-ounce and is about the size of a large plum. Most of his systems are in place, though there's still plenty of maturing to do. For one thing, his fetal digestive system is beginning to practice contraction movements so he can eat someday, and his bone marrow is busy making white blood cells — weapons against germs once he's out of your safe haven. The pituitary gland (at the base of the brain) has started producing the hormones that'll enable him (or her) to make babies of his (or her) own in a couple of decades or so. If all these changes sound dizzying, that may just be you dealing with yet another problematic pregnancy symptom: Lots of women experience occasional dizziness and/or feel faint due to progesterone, which causes increased blood flow to your baby by relaxing your own blood vessels. More blood flow to baby means less blood flow to your body and brain and that, along with typically lower blood-sugar levels during pregnancy, can set your world a-spinning. Do your part to keep your equilibrium by eating regularly, getting adequate rest, and standing up slowly.