How much tuna can you eat while pregnant?
Fish is recommended in pregnancy — but swordfish, shark and marlin are off the table.
Medically reviewed by Dr. Christopher Sterling, obstetrician ·
The short answer
You can eat tuna in moderation. UK advice is no more than four medium cans or two tuna steaks a week. Avoid high-mercury fish such as shark, swordfish and marlin, but do keep eating 2–3 portions of low-mercury fish a week.
Why it matters
Mercury builds up in large predatory fish and can affect a baby’s developing nervous system.
At the same time, fish provides omega-3 fats, iodine and protein that support brain development — so the advice is to choose fish carefully, not to avoid it.
US guidance (FDA) recommends 2–3 servings a week of “best choice” fish such as salmon, cod, sardines, shrimp and canned light tuna, and avoiding king mackerel, marlin, orange roughy, shark, swordfish, tilefish and bigeye tuna.
What to do
- Eat 2–3 portions of low-mercury fish a week.
- Limit albacore/white tuna and tuna steaks; canned light tuna is lower in mercury.
- Skip shark, swordfish and marlin entirely.
- UK: no more than 2 portions of oily fish (salmon, mackerel, sardines) a week.
Common questions
Is canned tuna safe during pregnancy?
Yes, in moderation. Canned light tuna is one of the FDA’s “best choices”; UK advice caps tuna at four medium cans a week.
Sources
Medically reviewed by Dr. Christopher Sterling, obstetrician, on against the sources above. Guidance can differ between countries — always follow the advice of your own midwife, doctor or pharmacist. Medical disclaimer.
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