Yes, if MSG doesn't bother you when you're not pregnant! Monosodium glutamate (MSG) is a natural component of many foods. It's a salt of the amino acid glutamine, and we always have some MSG in our bodies. Plus, it's commonly used to enhance the flavor of many foods, especially Asian food. The Food and Drug Administration (FDA) has been testing MSG for years and rates it "generally recognized as safe." However, the FDA requires that all foods containing MSG include that information on the label, because some people develop an adverse reaction to it, whether pregnant or not. In people who are sensitive to it, MSG can trigger headaches, nausea, vomiting, dizziness, and sleep disturbances. So you may want to avoid it during pregnancy, especially if you were sensitive to MSG before pregnancy. There's no evidence that MSG is harmful to a developing baby. In fact, it would be very difficult to ingest enough MSG to cause a problem. Even a large dose — which can cause nausea and vomiting even in someone who's not sensitive to it — wouldn't pose a known risk to a developing baby.
Lori Wolfe, Genetic Counselor. Is it safe to eat foods with MSG during pregnancy? In Baby Center [Online]. Available: http://www.babycenter.com/404_is-it-safe-to-eat-foods-with-msg-during-pregnancy_2285.bc