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Fish and Seafood: What's safe to eat during pregnancy?

Small mouth bass from Jordanelle Reservoir; brown trout from the Weber River; and catfish from Utah Lake: all of these fish contain methyl mercury, a metal that finds its way into in Utah streams, lakes and reservoirs.

Mercury particles get into Utah water ways through rain, snowfall and even dust. In recent years, mercury levels have become a concern to state agencies, who now issue fish and waterfowl consumption warnings for Utah waterways. Currently, fish in 14 different bodies of water, including Jordanelle and Pine Creek Reservoirs, the Weber River, Rock Creek, Pine Creek, and Joe's Valley Reservoir are subject to an advisory.

Methyl mecury works its way up the food chair through small organisms, which are consumed by the bugs, and then the birds, fish and other animals, and eventually humans. It is removed from the blood stream naturally over time. But, it may take over a year for that to happen, which means it can pass from mother to baby during that time. That's one of the reasons why Utah health and wildlife officials regularly issue "fish consumption advisories" on their website – www.fishadvisories.utah.gov - encouraging women who are planning to become pregnant or who are pregnant now to limit the amount of local fish they eat.

“Over time, high levels of mercury can cause brain damage and developmental delays.  And, so there are some fish that you definitely need to avoid.” Cara Munson, a registered dietician with the Utah Department of Health, says it's important to be aware of which types of fish are safe and which ones are not. “Large Predatory fish... like shark, tilefish, king mackerel should be avoided by pregnant women,” says Munson. “Smoked seafood would be a concern as well. That would be like refrigerated smoked seafood, like lox.”

Munson says cooked seafood is fine, but raw fish are a concern. She suggests cooking shellfish like mussels, clams and oysters until their shells pop open. And all fish should be cooked to an internal temperature of 145 degrees Fahrenheit. However, officials noter that heavy metals can not be cooked out of fish. Your best advice is to follow the fish consumption advisories for any fish that may contain mercury or other contaminants.

So, while sushi and other raw fish are not recommended, pregnant women, and those planning to be, should not avoid fish altogether.

“You should not be afraid of eating fish,” says McKell Drury with the Environmental Epidemiology program at the Utah Department of Health. “We still encourage everyone to eat fish; just choose wisely the fish that you eat.”

Here are a few facts:

  • Fish is very nutritious and packed with great nutrients. It is an excellent source of omega-3 fatty acids, B vitamins and lean protein. It is important that women eat fish during pregnancy.
  • The FDA recommends that you eat no more than 12 ounces of fish per week. But this recommendation only applies to those fish with lower levels of mercury, which include anchovies, king crab, catfish, salmon, shrimp, freshwater trout, sole, lobster (spiny/rock).
  • The serving recommendations decrease as the mercury level increases.
  • There are four types of fish to avoid: shark, king mackerel, swordfish and tile fish. These fish are considered to have the highest mercury levels and should not be eaten during pregnancy.
  • Canned, white albacore tuna has a higher level of mercury and should be eaten less often than canned, chunk light tuna.
  • You may eat up to six ounces per week of fish caught in local waters, but do not consume any other fish during that week. Check your local fish safety advisories.

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