Your friends, family, and doctor may have accepted that you are a vegetarian. If you become pregnant though, be prepared for that to change. These same people will often express strong doubt about the nutritional adequacy of your vegetarian diet now that you are pregnant. You yourself may wonder whether you should add meat to your diet.

Don't change your diet unless you want to. There is no need to eat meat just because you are pregnant or breastfeeding. You can get all the nutrients you need from a high quality vegetarian diet. It is probably not a good idea to become a vegetarian while you are pregnant or breastfeeding though. Becoming vegetarian is a major change, and your body is going through enough changes without the additional stress of changing your diet.

If you are pregnant or planning to become pregnant it's a good idea to make sure that you are eating a well balanced diet. While not eating meat can make you healthier, it doesn't guarantee it. Hopefully you have been following the advice on Savvy Vegetarian and are eating a great vegetarian diet!

A good vegetarian diet has a wide variety of fresh fruits, vegetables, grains, legumes (i.e. beans, lentils, and nuts) and some eggs and dairy or their equivalent. Fast food, highly processed junk foods, and canned fruits and vegetables are eaten rarely if at all.
If you are eating a balanced diet then it makes sense to assume that you just need to eat more of the same to meet the increased nutritional needs of pregnancy. This is basically true, but how much more? And more of which foods?

A pregnant woman needs only a small increase in calories; around 300 calories and 10-16 extra grams of protein. The body's need for certain nutrients increases significantly though. Every bite you take is important when you're pregnant. While the RDAs for almost all nutrients increase, especially important are folic acid, iron, zinc, and B12. Attention to adequate B12 is crucial for vegetarians who choose not to eat eggs and dairy. For more information on this topic, see Vegetarians, Are You Getting Enough Vitamin B12?

A lactating woman needs 500 extra calories and 12-21 extra grams of protein. This may be the only time in your life that you can eat large portions and lose weight.
Don't overdo it though. Not all women lose weight while breastfeeding. If you eat sensibly and exercise during and after your pregnancy a gradual return to your pre-pregnancy weight should not be too difficult.

A breastfeeding woman needs less folic acid, iron, and zinc than a pregnant woman but more B12. Calcium requirements stay the same (1200mg) whether you are pregnant, breastfeeding or not, so make sure that you are getting enough calcium in your non-pregnancy diet and you won't have to worry while you are pregnant or breastfeeding.