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Your Changing Body: Trimester by Trimester


Many first-time pregnant women think they know about the physical changes that accompany pregnancy, almost all of which they anticipate happening somewhere in the vicinity of their belly button. They expect to feel nauseated, to want to eat a lot, and to go to the bathroom with nearly comic frequency. All of these make a certain kind of sense, since they have something to do with the area where the baby is growing.

During my first trimester, however, I found myself out of breath after only a short walk. I didn't think it had anything to do with my pregnancy; after all, I wasn't even showing. How could the baby put pressure on my lungs? But when I looked it up in a reference book, I found it: breathlessness, a result of pregnancy hormones, common in the first trimester.

"I spend about 80 percent of my time with patients explaining that what they're experiencing is normal," says Thomas Moore, M.D., chairman of the department of reproductive medicine at the University of California, San Diego. And many of the often bizarre changes can be attributed to that familiar culprit: hormones. Some of the same ones that made you a little cranky and uncomfortable, or gave you blemishes in high school—primarily estrogen and progesterone—come back into play. Between the time of conception and your seven-month mark, they'll triple in quantity, then remain at that level until you deliver.

But just as every teenager reacts differently to puberty, every mom-to-be responds differently to this hormonal surge. For some, pregnancy is a time of glowing skin and high energy; for others, it's a return to concealers and an introduction to nearly constant nausea. Some are highly sexual, others lose their desire; some are ravenous, others can barely force anything down.

Doctors don't know why there's such a wide range of reactions. What they do know is that in all pregnant women, the hormones work toward the same goals. To start with, they instruct the kidneys to retain salt and water in order to build blood volume. By her seventh month, a pregnant woman will have 40 percent more—enough to circulate through the placenta. To help cope with this increase, which would normally cause high blood pressure, the hormones also lower blood pressure, which allows the heart to do more without added stress. As part of this process, progesterone relaxes the involuntary muscles of the intestines, bladder, stomach, and kidneys. Connective tissue and ligaments also loosen, to help the baby pass through the pelvis more easily.

But while such side effects as nausea, backaches, and leg cramps are part and parcel of creating a healthy infant, they aren't much fun for Mom. "The baby is taking you over," says Dr. Moore, "and he isn't doing it for your well-being."

Thankfully, most symptoms aren't threatening. But since a few can be a sign of more serious problems, bring any to the attention of your obstetrician. For benign conditions, the main thing she'll offer—aside from home remedies and certain over-the-counter drugs—is reassurance. The good news is, many women find maladies ease as they enter the next trimester (even if new ones arise). From head to toe, changes you might not expect:


Side effects: Ill-fitting contact lenses and altered vision, nosebleeds, nasal congestion, headaches, dizziness, bleeding gums, patchy-colored skin

With increased blood circulation, your entire body will be a little swollen. About 10 weeks into your pregnancy, you may find contacts don't fit as well over enlarged eyes, and your vision may not seem as sharp—both temporary conditions. If you experience a sudden onset of blurry vision, however, check with your obstetrician immediately. It may signal dangerously high blood pressure, known as preeclampsia.

Engorged nasal tissue can bring on nosebleeds and stuffiness. But allergy sufferers may find relief: Strong immune reactions trigger allergies, and progesterone and higher levels of the hormone cortisone suppress the immune system.

Many women also experience headaches in the first trimester, which can be blamed on low blood sugar—the result of your changing metabolism—or reduced blood flow to the brain when you stand or sit up quickly. "Your uterus has first dibs on your blood supply," says William Sears, M.D., a Parenting contributing editor and coauthor of "The Pregnancy Book." Dizziness occurs for the same reason.

Extra fluids can also create excess saliva, as well as swollen and bleeding gums. And some women develop tiny growths on their gums. "They're probably a result of the same hormones that are helping your body grow your baby, and will disappear after delivery," says Dr. Sears.

Finally, your cheeks may glow (from oil-gland secretions, plus more blood to the skin) or sport brown or yellow patches (increased estrogen and progesterone result in more pigment, especially noticeable when exposed to the sun). This discoloration is similar to what some women experience when taking the Pill.

Hands, Wrists, and Arms

Side effects: Carpal tunnel syndrome, red palms

In the third trimester, because of fluid retention, the nerves snaking through tiny passageways are likely to be pinched by swollen tissue, which can lead to, or worsen, carpel tunnel. Occasionally, the shooting pain, numbness, and tingling can migrate to the forearm and shoulder.

As veins enlarge to accommodate greater blood volume, and capillaries branch out to handle the increase, the skin all over your body enjoys greater blood flow. Consequently, some women's palms (or soles of the feet) become reddened after about 12 weeks.