It may be difficult to get everything you need from your diet, especially essential nutrients such as folic acid and iron, so most providers recommend a prenatal vitamin "as an insurance policy," says Dr. Richard Schwarz, chairman of obstetrics and gynecology at New York Methodist Hospital. Your iron needs to double to 30 milligrams to accommodate increased blood volume during pregnancy; a lack of iron can cause anemia. Women should already be taking a prenatal vitamin with 400 micrograms, or 0.4 milligrams, of folate three months before conception to help prevent neural-tube defects. Your doctor or midwife may recommend supplements if necessary.

You should also be drinking at least eight 8-ounce glasses of fluid a day, mostly water if possible, since dehydration can bring on premature labor. Fluids also will help reduce muscle cramps, swelling and urinary tract infections. "I tell patients to drink, drink, drink. Their urine should be so pale they can't see it in the toilet," says certified nurse-midwife Katherine Puls. If drinking with food exacerbates morning sickness, try filling your quota between meals rather than with them.

A Pregnant Pause on Thinness

One thing to keep in mind is that you'll gain about 25 to 35 pounds during your pregnancy. That isn't always easy to take, especially as the scale tips into never-before-seen territory, and you start feeling more and more like a beached whale. Most women will gain about 2 to 4 pounds during the first trimester, although some will stay the same or even lose a few pounds until morning sickness passes. A weekly gain of 1 pound during the second and third trimesters is common as your baby grows faster.

"Women get really uptight because for so long they've been fighting to keep their weight in line and now all of a sudden we're telling them to gain this much weight," says Ward. "But if you don't eat enough and gain enough weight, you'll have a baby that could be affected for the rest of its life because you wanted to preserve your figure." Women who don't gain enough weight in pregnancy are more likely to have small babies, and those smaller than 5 ½ pounds have a harder time surviving.

The gain can be especially difficult for those who battle anorexia or bulimia, but often the responsibility of bringing a new life safely into the world is enough impetus for women to overcome their eating disorders, if only temporarily. Puls often recommends keeping a daily planner to record what you've eaten, since eating disorders are often associated with control.

"I was not going to hurt my babies," says one woman, who did not want her name used because she still battles anorexia. During both her pregnancies, she managed to eat three meals a day and get the recommended nutrition. She gained 33 pounds each time, and her babies, both healthy, weighed 8 pounds. "Those are the only times since I was 18 years old that I didn't have an eating disorder," she concedes. Still, it was a struggle, and she obsessed about her weight. "I was really paranoid. But if I was good ... then on the days I weighed in, I'd go to the bakery after and reward myself with a smiley cookie."

If you are either under- or overweight, make sure you've discussed with your doctor or midwife an appropriate weight range to target. Women who start out underweight will probably have to gain more than the average mom-to-be, and those who weigh too much may be advised to gain less, in addition to being monitored for associated problems, such as high blood pressure and diabetes. If you're carrying twins, the American College of Obstetricians and Gynecologists recommends a weight gain of 45 pounds.

Don't get too hung up over every pound, though. "To me, the scale is not the end point," says Puls, who practices with two obstetricians. "The scale is an indicator, and if it's going up too fast then you have to look at nutrition and exercise. If it's not going up fast enough, then you need to look at nutrition. I don't use the scale to say, 'Oh, you gained too much' or 'Oh, you gained too little.'"

And remember: You can get your figure back; it just might take a year to lose all the weight and to regain muscle tone, Ward says. Within six weeks, you'll probably lose 15 to 20 pounds (from the baby, placenta, extra blood volume and fluids), although if you breast-feed, those last pounds may linger until you've weaned your baby. Milk production requires about 800 calories a day, with only about 300 available from stored fat. That's 500 extra calories derived from your diet -- 200 more than you needed while pregnant.

Foods With an Rx

The term "comfort food" takes on a whole new meaning when you're pregnant, since certain foods or eating habits can actually help ward off some of the aches and pains of pregnancy. To quell morning sickness, heartburn and indigestion, eat small, frequent meals with bland starches, such as rice, bread or pasta, and avoid greasy or spicy foods. Herbal teas, like ginger root and lemon herb, can soothe your stomach, as can antacids, which also are a source of calcium.

Experts advise women to consult their doctor or midwife -- and find a reputable herbalist -- before using herbs while you're pregnant. Although they're natural, not all of them are harmless. Some may cause allergic reactions, and some may even be harmful to your growing fetus, especially those that act as strong laxatives or promote uterine contractions. Puls often recommends Susun Weed's "Wise Woman Herbal for the Childbearing Year" for information on herbs that can be used during pregnancy.

Constipation and hemorrhoids often experienced during pregnancy can be alleviated by a diet rich in fiber, which comes from whole grains, fruits, vegetables, legumes, nuts and seeds. Leg cramps, which might be caused by a shortage of calcium or magnesium, may be minimized by adding dairy foods, dark green vegetables, calcium-enriched foods like orange juice, or even antacids.