By Morgan Roan
University of Georgia

After the first three months, the woman needs to consume about 300 calories more each day than usual. "An increase in healthy foods is best," she said. "You don't have to eat a lot of extra food to raise your caloric intake. One sandwich or three cups of skim milk will satisfy the extra 300 calories."

Pregnant women should follow the guidelines suggested by the U.S. Department of Agriculture Food Guide Pyramid. Eat at least three meals with one or two snacks each day. "Small, frequent meals are best," she said.

"The average woman gains half a pound to 1 pound each week after the first trimester," Crawley said. "Most women only gain 1 to 4 pounds during the first trimester. An average-size woman will gain 25 to 30 pounds while pregnant."

Folate

It's important for women of child-bearing age to take folate before they get pregnant, Crawley said. This will prevent neural-tube defects like spina bifida, a problem of spine development, and anencephaly, a poorly formed brain and skull.

"The major organs of the baby are formed within eight weeks of pregnancy," she said. "This is why it's important for the woman to take 400 micrograms of folate in a supplement before and after conception."

Many multivitamins or prenatal vitamins contain the right amount of folate. Always check the label to be sure.

Calcium

Calcium helps the baby's bones grow properly and protects the mother's bones. Pregnant women should take about 1,500 milligrams each day. Calcium is found in milk, other dairy products, calcium-fortified juices, leafy green vegetables, fortified soy milk and calcium supplements.

Fiber

To help prevent constipation, a common problem during pregnancy, pregnant women should eat more fiber. "Whole grains are a better source of fiber than refined grains," she said. Five to seven fruits and vegetables a day are good, too.

Iron

Meats, dried beans and peas and dark leafy green vegetables are good sources of iron. Eating enough of these foods will prevent iron deficiency. Doctors will tell most pregnant women to take an iron supplement, too.

Foods to avoid

Some foods, such as swordfish, shark, tuna steaks and other large fish, contain high levels of mercury. Don't eat these in large amounts. They may cause neurologic damage to the baby.

Cook meats well to kill the bacteria that could cause serious complications for the unborn child. "Even precooked meats such as lunch meat and hotdogs should be heated," Crawley said, "to kill any bacteria."

A harmful bacterium called Listeria monocytogenes can be found in soft cheeses (like feta, Brie, Camembert, blue-veined cheeses and Mexican-style cheeses like "queso blanco fresco") that may be made with inadequately pasteurized milk. This bacterium can cause miscarriage, premature birth, blood poisoning or other life-threatening complications.

"Cream cheese and aged cheeses are safe to eat," Crawley said. "Another safety suggestion is to rinse vegetables and fruits with water and wipe them off well before eating."

Exercise

It's safe to exercise during pregnancy. Running and other strenuous lower-body exercises, though, aren't good. They may put a lot of stress on the baby.

"Walking or swimming is better because it promotes more rhythmic motion than bouncing," Crawley said.

During pregnancy, perform exercises that won't throw your balance off. "Water exercises are best," she said. "They're supportive and relaxing."