Yes, you can. Here are some guidelines.
Protein
Like all pregnant women, you need about 60 grams of protein daily and 100-300 more calories than before you were pregnant (or enough to support suggested weight gain). If you don’t have adequate calories, your body will break down some of the protein for energy. Most vegetarians simply add an extra daily serving or two of the same protein foods they usually eat.
B12
If you eat dairy and eggs, you can get adequate B12 in your diet. If you are vegan (no animal products), you will need to supplement your diet with B12. B12 is important for baby’s developing nervous system and helps you and baby form new red blood cells. The general recommendation for B12 for pregnant women is 2.6 micrograms daily.
Some vegetarian groups teach that humans can get adequate B12 from what bacteria in our system produce. While this is true in some herbivores, research has not demonstrated that humans can get adequate B12 this way. We encourage you to supplement your diet.
Note: B12 can be destroyed by stomach acids. Many B12 supplements are designed to be dissolved under the tongue. This method allows much of the B12 to absorb directly, by-passing the stomach acid. If you take these types of supplements, make sure that you let them dissolve under your tongue instead of swallowing them whole.
Calcium
Well meaning friends are sure to advise you, “You HAVE TO drink milk while you are pregnant.” Milk can be a good source of calcium (and of protein) but it is not the only source. You need 1000 mg of calcium daily. Some good vegetarian sources include collards, kale, almonds, various greens, and fortified cereals.
Fat-soluble vitamins
Some vegetarian diets are lower in fat than non-vegetarian diets. Make sure you are getting some healthy fats. Nuts and nut butters, olives and olive oil, avocados… there are many healthy vegetarian fats
Iron
During pregnancy you need 27 mg of iron daily. Iron can be found in some whole grains, seeds, nuts, legumes, and in molasses. The best research currently recommends an iron supplement for all pregnant women.
Weight gain
Many vegetarian diets are lower in calories than non-vegetarian diets. Make sure you are eating enough calories to gain the recommended amounts for your pre-pregnancy weight. Baby is growing rapidly and needs enough calories to grow, to say nothing of supporting all that kicking and squirming that you may be feeling by now!
Soy
Research isn’t conclusive but it offers some concerns about large amounts of soy during pregnancy or lactation because of soy’s estrogenic-type effects. Play it safe and keep your soy intake moderate. There are many other wonderful vegetarian sources of protein.
Like any major change, there is a “learning curve” to becoming a vegetarian. Some practitioners feel that there are body chemistry changes as you switch to a completely vegetarian diet. By all means include some of those delicious vegetarian recipes in your diet but don’t eliminate the meat all at once.
Make sure that you talk with your obstetrician about being vegetarian during pregnancy so that he or she can make sure that you and your baby are in optimum health.
This section contains articles and guidance for healthy eating whether you are working on becoming pregnant, expecting or have a new baby. Articles cover information including what to eat, controlling nausea, breastfeeding and vitamins.