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Is it safe? · Pregnancy Smart

Is tilefish safe during pregnancy?

Assigned clinical reviewerPerry Friedman· MD, FACOG-MFMDraft · pending clinical reviewUpdated

What does the evidence say about tilefish during pregnancy?

  1. Tilefish from the Gulf of Mexico is named on MotherToBaby's list of fish with the highest methylmercury levels, alongside shark, swordfish, king mackerel, and marlin, and the guidance is to avoid all of them during pregnancy and breastfeeding. 1
  2. FDA and EPA's joint fish advice splits tilefish by where it's caught: Atlantic Ocean tilefish is listed as a Good Choice, safe at one serving a week, while Gulf of Mexico tilefish is a Choice to Avoid, flagged for the highest mercury levels of any fish on the list. 2
  3. FDA's own testing data shows why: Gulf of Mexico tilefish averaged 1.123 parts per million of mercury across sampling, compared with 0.144 parts per million for Atlantic tilefish, nearly eight times lower. 3
  4. Methylmercury crosses the placenta and can be found in fetal blood at levels higher than in the blood of the pregnant person, which is the reason the highest-mercury species get singled out rather than fish as a whole. 1
  5. A systematic review found that moderate fish intake during pregnancy, generally one or more servings a week, was linked to better offspring neurodevelopmental outcomes in most of the studies it examined, provided the fish chosen is low in mercury. 4

Is tilefish safe in each trimester?

  • First trimester. The Gulf-versus-Atlantic distinction matters in every trimester, so there's no early window where Gulf of Mexico tilefish is fine. If you already ate some before learning the difference, MotherToBaby's guidance is that eating from the highest-mercury list one time is not likely to increase the chance of problems. Mention it at your first visit, then move on.
  • Second trimester. Menus rarely list where a fish came from, and tilefish is easy to mistake for a milder, lower-mercury white fish. Asking your server or fishmonger whether it's Atlantic or Gulf of Mexico tilefish takes a moment and settles the question either way.
  • Third trimester. Methylmercury crosses the placenta and shows up in fetal blood at higher levels than in the pregnant person's own blood, and the concern builds with steady intake over time rather than any single dinner. If Gulf tilefish has been a regular habit, bring that up with your provider rather than trying to sort it out on your own.

Frequently asked questions

Why is tilefish on the FDA 'avoid' list?

Only Gulf of Mexico tilefish is on FDA's Choices to Avoid list, and it's there because it tests at the highest mercury levels FDA has measured in any commercial fish, even higher than swordfish or shark. Atlantic tilefish is a separate, much lower-mercury fish that FDA rates a Good Choice.

Is Gulf of Mexico tilefish different from Atlantic tilefish?

Yes, dramatically. FDA testing found Gulf of Mexico tilefish averages 1.123 parts per million of mercury, compared with 0.144 parts per million for Atlantic tilefish, nearly eight times lower. If a menu or fish counter doesn't say which one you're getting, it's safest to ask or skip it.

What other fish are on the FDA high-mercury avoid list?

MotherToBaby's list of fish to avoid during pregnancy and breastfeeding is bigeye tuna, shark, king mackerel, swordfish, marlin, Gulf of Mexico tilefish, orange roughy, and whale meat. These are all large, long-lived fish that eat other fish, which is how mercury builds up in their tissue over time.

What are low-mercury alternatives to tilefish?

FDA's Best Choices list, meant to be eaten two to three times a week, includes salmon, cod, shrimp, and canned light tuna. Atlantic tilefish itself is a Good Choice at one serving a week if you can confirm that's what you're being served.

Related in the library

References

  1. Methylmercury: MotherToBaby Fact Sheet

    MotherToBaby · https://mothertobaby.org/fact-sheets/methylmercury-pregnancy/

  2. Advice about Eating Fish, FDA and EPA

    FDA · https://www.fda.gov/food/consumers/advice-about-eating-fish

  3. Mercury Levels in Commercial Fish and Shellfish (1990-2012), FDA

    FDA · https://www.fda.gov/food/environmental-contaminants-food/mercury-levels-commercial-fish-and-shellfish-1990-2012

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.