Is Tuna Safe During Pregnancy?

The short answer: yes, with firm limits

Tuna is safe to eat during pregnancy as long as you respect the type and the amount. Canned light tuna is the lower-mercury choice and is fine in normal portions. Albacore (white) tuna and yellowfin (ahi) carry more mercury, so the FDA and EPA cap them at a single 4-ounce serving per week, and in any week you eat one of those, you should eat no other fish at all.

This is a caution, not a green light. The difference between safe and risky here comes down to which can you reach for and how often, so it is worth getting the numbers right before you build your meals around it.

Why mercury is the real concern

The issue is methylmercury, a form of mercury that builds up in fish as larger, longer-lived predators eat smaller ones. Tuna sit fairly high on that food chain, so they accumulate more of it than small fish like sardines or anchovies. The bigger and older the tuna, the more mercury it tends to hold.

Mercury matters in pregnancy because it crosses the placenta and can affect a developing baby's brain and nervous system, which are growing rapidly throughout all nine months. The goal is not to avoid fish, which provides protein and the omega-3s that support that same development, but to choose lower-mercury fish so you get the benefit without the build-up.

Exactly how to eat tuna safely

Follow the current FDA and EPA categories. Canned light tuna is a Best Choice: you can have up to two to three servings a week, which is roughly 8 to 12 ounces total across all your Best Choice fish combined, not on top of them. One serving is about 4 ounces, or the size of your palm.

Albacore or white tuna and yellowfin (ahi) tuna are Good Choices, which means one 4-ounce serving per week at most. Crucially, in any week you eat a Good Choice fish, you should eat no other fish that week. Cook tuna steaks thoroughly to an internal temperature of 145 degrees Fahrenheit, and skip raw tuna such as sashimi, poke, and seared rare ahi while pregnant.

Does the trimester change anything?

The limits stay the same across all three trimesters. Because mercury can accumulate in your body over time and the baby's brain develops from start to finish, there is no trimester where albacore or yellowfin suddenly becomes unlimited.

If anything, consistency is the point. Spreading two to three servings of low-mercury fish across each week, rather than eating a large amount at once, gives you steady omega-3s while keeping mercury exposure low throughout the pregnancy.

A note on breastfeeding

The same FDA and EPA guidance applies while breastfeeding, since small amounts of mercury can pass into breast milk, so keep favoring canned light tuna and treat albacore and yellowfin as the once-a-week Good Choice option.

When to call your provider

Reach out if you realize you have been eating well over these amounts, especially a lot of albacore, yellowfin, or other high-mercury fish, and your provider can advise whether any follow-up is needed. Also check in if you have symptoms like unusual numbness, tingling, or tremors, or if you simply want help fitting fish into your diet alongside any other conditions you have.

The bottom line

Stick to canned light tuna for everyday eating, cap albacore or yellowfin at one 4-ounce serving in a week with no other fish that week, always cook it through, and tuna stays a safe, nourishing part of your pregnancy.