If you're a pregnant vegetarian, don't worry: nobody's going to make you trade your humus for a cheeseburger.

In fact, babies born to vegetarian moms are just as healthy as other infants, according to experts at the American Dietetic Association. "Vegetarians do fine during pregnancy," says Elizabeth Ward, M.S., R.D. "They do just as well as mainstream eaters, as long as they know the pitfalls."

Ward offers tips for vegetarians who are eating for two in her book, Pregnancy and Nutrition: Good Health for You and Your Baby (John Wiley, 1998).

For vegetarians, it can sometimes be difficult to gain enough weight, Ward says. Doctors usually advise women to put on an extra 25-35 pounds during pregnancy. To do that, you need to eat an extra 300 calories per day, experts say. "Weight gain during pregnancy is linked to birth weight," Ward says. "And birth weight is linked to the baby's health."

One way to boost calories is to add oil and salad dressing to the dishes you prepare. Try to eat rich foods like nuts and peanut butter. Eating small, frequent meals during the day also helps. Vegetarians who include eggs and milk products in their diet should be fine, Ward says, but vegans--who rule out all animal products-- may have to work harder to get enough protein, a key building block for human life.

Vegans also should take extra calcium, zinc, and vitamin B12 (only found in foods that come from animals). Since vegan dietary needs are more complex, Ward suggests at least one session with a nutritionist before becoming pregnant. In fact, all pregnant women are at a higher risk for developing anemia as their bodies work to increase the blood supply for the growing baby. For that reason, Ward says, every pregnant woman should take an iron supplement.

Folic acid, which prevents birth defects, is another critical ingredient to add to the mix. Vegetarians naturally get more folic acid in their diet because they eat more fruits and vegetables, but the American Dietetic Association says it's still a good idea to take a supplement with at least 400 micrograms of folic acid.

To order fact sheets on vegetarian diets in pregnancy, visit the American Dietetic Association's Web site: www.eatright.org.