The following questions-and-answers on safe fish consumption before conception and during pregnancy come from Eating for Pregnancy: The Essential Nutrition Guide and Cookbook for Today’s Mothers-to-Be, winner of the 2009 Mom’s Choice Gold Award! As Diane Snyder, MD, OB/GYN said: “As an obstetrician this is a welcome resource for our patients. We often wish we had more time during prenatal visits to review healthy eating and recommendations for adequate nutrition. This book is a welcome addition.” This information is from a text box on page 320.
What is mercury and methylmercury?
Mercury occurs naturally in the environment, and it can also be released into the air through industrial pollution. Mercury falls from the sky, accumulating in streams and oceans, where it turns into methylmercury in the water. Fish absorb methylmercury as they feed. High amounts of methylmercury in certain types of fish can potentially be harmful to the neurological development of an unborn baby and young child.
Is there methylmercury in all fish and shellfish?
Nearly all fish and shellfish contain traces of methylmercury. Large fish (swordfish, shark, king mackerel, and tilefish) with long lifespans have the highest levels of methylmercury, mainly because they’ve had more time to accumulate it. These fish pose the greatest risk. Other types of fish should be eaten in amounts recommended by the FDA and EPA.
What about fish sticks and fast food sandwiches?
Fish sticks and fast-food sandwiches are usually made from fish that are low in mercury, so they are safe to eat.
What about tuna steaks?
Because tuna steak generally contain higher levels of mercury than canned light tuna, you may eat up to 6 ounces (one average meal) of tuna steak per week.
What if I eat more than the recommended amount of fish and shellfish in a week?
One week’s consumption of fish does not change the level of methylmercury in your body much at all.
I’m trying to conceive. Should I be concerned about methylmercury?
If you regularly eat fish high in methylmercury, it can accumulate in your bloodstream over time. Methylmercury is excreted from the body naturally, but it may take over a year for high levels to drop significantly. Therefore, it may be present in a woman before she becomes pregnant. For this reason, women who are trying to conceive should also try to avoid eating high-mercury fish, but they certainly should eat other fish.
Source: EPA, U.S. Environmental Protection Agency [Internet]. Fish Advisories, Consumption Advice, Joint Federal Advisory for Mercury in Fish, “What You Need to Know about Mercury in Fish and Shellfish, 2004 EPA and FDA Advice for Women Who Might Become Pregnant, Women Who Are Pregnant, Nursing Mothers, and Young Children.” [last updated August 14, 2008; cited September 2008]. Available from www.epa.gov/waterscience/fishadvice/html.
More about Fish, Methylmercury, Omega-3, Safe Fish

As the spring and summer grilling season kicks off, here are some tips to help you navigate the seafood counter or your local fish market! Remember, too, that your fishmonger is a terrific source of knowledge. Ask him or her about amounts, best cuts, and optimal cooking methods and times. If you are not going home right after shopping, request to have your seafood placed in a bag of ice. Enjoy!