Check out what happened with your little one's development last week.
Extra eggs. You probably don't know the gender yet, but if you're carrying a girl, the reproductive system is already well established. The vagina, uterus, and fallopian tubes are in place, and the ovaries contain more than 6 million primitive egg cells. When your baby is born, that number will have shrunk to about 1 million, which is all the eggs she'll ever have. Isn't it fascinating to know that the egg that became your baby is as old as you are, that it was just waiting to be released while you were growing up?
You've got male. If you're having a boy, things are also moving along. The male reproductive system is nearly fully developed. Testicles have formed and have been secreting testosterone since about week 10 of your pregnancy. The external genitalia, which became male in the first trimester, are continuing to grow: A scrotal sac is usually evident by now.
Second skin. "What's this creamy stuff all over my body?" Around this time, the skin starts to produce a creamy substance called vernix caseosa, which is made of oils secreted by the skin, dead cells, and lanugo, the fine hair that covers the body. This waxy coating protects your little one's skin from the effects of floating in amniotic fluid. Most of the vernix will disappear before birth, unless your baby arrives early. Preterm babies are often born still covered with a lot of vernix. Even full-term infants will have a bit of vernix in the creases of their skin.
Measuring up. Your little one measures about 7 inches and weighs anywhere from 6.5 to 8 ounces. There's a definite upswing on the fetal growth chart now, so expect some big gains in the coming weeks.
Funny face. Don't try to wash off the dark patches on your nose, cheeks, and forehead. They're not dirt—they're a common condition of pregnancy called chloasma, or the "mask of pregnancy." Hormones are to blame for this splotchiness, which affects some but not all pregnant women. Pregnancy hormones are also responsible for the linea nigra, the dark line running down your belly to your pubic bone. Both chloasma and the linea nigra will gradually fade after you give birth. Exposure to the sun can darken the pigments in your skin even more, so be sure to use sunscreen and stay in the shade if you want to keep a more even skin tone. Using sunscreen daily is a good habit to start now, in any case.
Round ligament pain. As your uterus grows larger, the round ligaments that support it must stretch. Occasionally, these stretched-out ligaments will cause a sharp pain or a dull ache in your lower abdomen, usually on one side or the other. It's probably most noticeable when you change positions suddenly or get up from a chair or bed. As with most discomforts during pregnancy, rest usually offers the best relief. Although round ligament pain is pretty common, you should call your doctor, midwife, or nurse if you're worried.
From the experts. True or false: You need to toughen your nipples during pregnancy to prepare for breastfeeding. "False," says Suzanne Dixon, M.D., M.P.H. "This is really old advice. In fact, it can be harmful, since breast stimulation can release the hormone that causes your uterus to contract." However, if you have inverted nipples—those that go in when stimulated—your health care provider may suggest strategies to make breastfeeding easier once your baby is born. To learn more from Dr. Dixon, click here.