Pregnancy and fish: What's safe to eat?

If you're confused about whether it's safe to eat seafood during your pregnancy, you're not alone. Understand the guidelines for pregnancy and fish.

By Mayo Clinic Staff

If you're pregnant, you might feel like you need to become a nutrition expert overnight. After all, what you eat and drink — and what you avoid — influences your baby's development. Some choices are logical, such as eating plenty of fruits and vegetables and eliminating alcohol from your diet. But what about seafood?

Here, Roger W. Harms, M.D., a pregnancy specialist at Mayo Clinic, Rochester, Minn., and medical editor of "Mayo Clinic Guide to a Healthy Pregnancy," offers practical advice about pregnancy and fish.

What's the link between pregnancy and fish?

Seafood can be a great source of protein, iron and zinc — crucial nutrients for your baby's growth and development. In addition, the omega-3 fatty acids in many fish can promote your baby's brain development.

But some types of seafood — particularly large, predatory fish such as shark, swordfish, king mackerel and tilefish — can contain high levels of mercury. Although the mercury in seafood isn't a concern for most adults, special precautions apply if you're pregnant or planning to become pregnant. If you regularly eat fish high in mercury, the substance can accumulate in your bloodstream over time. In turn, too much mercury in your bloodstream could damage your baby's developing brain and nervous system.

How much seafood is recommended?

The Food and Drug Administration (FDA) and the Environmental Protection Agency (EPA) say pregnant women can safely eat up to 12 ounces (340 grams) of seafood a week. Similarly, the 2010 Dietary Guidelines for Americans recommend 8 to 12 ounces of seafood a week for pregnant women — or about two average meals.

Not all researchers agree with these limits, however, citing a study that noted no negative effects for women who ate more seafood than the FDA-approved guidelines.

What's safe to eat?

Eat a variety of seafood that's low in mercury and high in omega-3 fatty acids, such as:

  • Salmon
  • Anchovies
  • Herring
  • Sardines
  • Trout
  • Atlantic and Pacific mackerel

Other safe choices include shrimp, pollock and catfish. However, limit albacore tuna and tuna steak to no more than 6 ounces (170 grams) a week. Also, be aware that while canned light tuna on average appears safe, some testing has shown that mercury levels can vary from can to can.

Sep. 04, 2014 See more In-depth