Can a Pregnant Woman Eat Tuna Sandwich? | Tuna Truths

It depends on the type of tuna and the mother’s weight, but a pregnant woman can eat a tuna sandwich in moderation by choosing canned light (skipjack) tuna and limiting total weekly fish intake to 12 ounces.

You’ve probably heard the warning: limit tuna during pregnancy because of mercury. But does that mean you have to give up your favorite tuna sandwich entirely? Not exactly. The advice is more nuanced than a blanket “no.”

The short answer is yes — a pregnant woman can eat a tuna sandwich, as long as she picks the right tuna and sticks to recommended weekly limits. Canned light (skipjack) tuna is a “Best Choice” low-mercury fish, while albacore (white) tuna and tuna steaks should be limited more strictly.

The Short Answer on Tuna Sandwiches in Pregnancy

The FDA and EPA advise pregnant women to eat 8 to 12 ounces (2 to 3 servings) of low-mercury fish per week. A tuna sandwich typically uses about 5 ounces of canned tuna (drained), which counts as one serving.

For a standard tuna sandwich made with light tuna, you can safely have about two per week as part of that total. If you prefer albacore (white) tuna, limit it to one sandwich per week (6 ounces of tuna) and skip other fish that week.

The NHS notes that mercury can cross the placenta and affect the developing nervous system, which is why limits exist. But moderate consumption of low-mercury fish like light tuna is considered safe and even beneficial, providing omega-3s that may support fetal brain development.

Why Mercury and Tuna Raise Red Flags

The concern about tuna in pregnancy comes down to mercury — a heavy metal that builds up in larger, longer-living fish. Pregnant women hear “avoid mercury” and sometimes cut out all fish. But the real risk is from high-mercury species like bigeye tuna, swordfish, and shark, not from moderate amounts of low-mercury tuna.

• Canned light (skipjack) tuna: This is the lowest-mercury option, considered a “Best Choice” by the FDA/EPA. It can be eaten up to 12 ounces per week.
• Albacore (white) tuna: A “Good Choice” with moderate mercury. Limit to 6 ounces per week — about one standard sandwich.
• Tuna steak (fresh or frozen): Similar to albacore — limit to one serving (6 ounces) per week and avoid other fish that week.
• Avoid high-mercury fish entirely: Bigeye tuna, king mackerel, marlin, orange roughy, swordfish, shark, and tilefish should be completely avoided during pregnancy.

The bottom line: not all tuna is created equal. Choosing the right type and sticking to the suggested portions keeps both you and your baby safe while letting you enjoy a classic lunch staple.

How Much Tuna Can You Eat? Weekly Limits by Type

The FDA and EPA break down tuna into two categories with different weekly limits. Here’s how the most common forms stack up in terms of safe consumption during pregnancy. The full breakdown is available in the FDA EPA fish advice.

Keep in mind that these are maximums, not targets. You don’t have to eat tuna every week; the advice simply sets safe upper limits. If you eat a tuna sandwich one week, you can still have other low-mercury fish like salmon or shrimp.

Building a Safe Tuna Sandwich

Making a pregnancy-safe tuna sandwich comes down to three things: choosing the right tuna, handling it properly, and keeping portions in check. Here’s a step-by-step guide.

1. Choose light tuna. Check the label for “skipjack” or “chunk light.” Avoid “white” or “albacore” if you plan to eat more than one sandwich per week.
2. Stick to one serving. A standard 5-ounce can (drained) counts as roughly one serving. Use the whole can for one sandwich, and limit sandwiches to 2 per week with light tuna (or 1 with albacore).
3. Include safe mix-ins. Mayo, celery, pickles, and spices are fine. No raw sprouts or unpasteurized cheese on the side.
4. Ensure fully cooked. Canned tuna is pre-cooked and safe to eat cold straight from the can. If you’re using fresh tuna, cook it to 145°F internal temperature.
5. Vary your fish. Don’t eat tuna every week. Rotate with other low-mercury choices like salmon, tilapia, or sardines to minimize any single mercury source.

A tuna sandwich made this way fits easily into a pregnancy diet. It provides protein, healthy fats, and a satisfying lunch — all within the guidelines that major health organizations have established.

Other Low-Mercury Seafood Options

Tuna isn’t the only safe seafood during pregnancy. A variety of fish offer omega-3s and lean protein with even lower mercury levels. The NHS and FDA recommend these options as part of the 8–12 ounce weekly quota.

Tuna’s higher mercury content compared to other fish is why the NHS tuna mercury page advises limits. Modest amounts of light tuna are still fine, but you have plenty of alternatives.

Rotating these options alongside occasional tuna helps you get the benefits of seafood without worrying about cumulative mercury exposure. Aim to eat two to three servings of low-mercury fish spread throughout the week.

The Bottom Line

A tuna sandwich is safe during pregnancy when you use the right tuna — preferably canned light (skipjack) — and stick to the FDA’s weekly limit of 12 ounces (2–3 servings). Albacore and tuna steaks should be limited to 6 ounces per week. Vary your seafood choices to keep exposure low.

If you’re unsure about your overall fish intake, your obstetrician can review your diet and help adjust weekly limits based on your individual health needs and blood mercury levels if needed.