Transcript: You love tuna and other fish dishes, but, oh mercy, the mercury! Mercury compounds, like methylmercury, are chemical byproducts dumped into our oceans and rivers, which can contaminate some of the fish we eat. While mercury hasn’t yet been shown to significantly harm adults, it can be extremely bad for babies. When a pregnant woman ingests mercury from fish, it can pass easily through a mother’s body into her baby’s placenta. This metal is toxic to a baby’s nervous system and can result in disabilities ranging from cerebral palsy to mental retardation. For this reason, it is wise to avoid large, high-mercury fish while pregnant, including: shark, swordfish, king mackerel and tilefish. Another worrisome fish is tuna, which tends to have a moderate level of mercury.  Tuna isn’t completely off-limits, but pregnant women should limit their consumption of it, and avoid tuna steaks and filets, which have been shown to be high in the toxin. Instead, stick to light, canned tuna, and don’t consume more than six ounces of it a week.  You can feel safe about consuming smaller fish, like sardines, catfish and tilapia. Most shellfish is fine, as well, with the exception of lobster, which, like tuna has moderate mercury content. Unfortunately, methylmercury remains in your system for up to a year after it is consumed. A. Because mercury consumed even prior to pregnancy can harm a fetus, B. it’s wise to minimize dangerous fish if you’re trying to conceive. However, if you became pregnant unexpectedly and know that you’ve consumed large amounts of mercury, don’t panic – it most likely won’t have any consequences. However, you should stop eating fish that have mercury, and talk to your doctor. If you are concerned, you can always have a test performed to ascertain the level of mercury in your system. Today’s pregnant woman needs to be very careful to minimize her mercury intake, but remember, just because mercury is bad for you doesn’t mean you should stop eating fish.