Fish is one of the better things to eat in pregnancy, and the guidance is about which fish, not whether to eat it at all. That distinction gets lost, and plenty of women end up avoiding it entirely.
Two to three servings a week of low-mercury fish is recommended, not discouraged.
Fish supplies omega-3 fatty acids for the baby’s brain and eye development, along with protein, iodine and vitamin D. Avoiding it altogether means losing all of that to avoid a risk that applies to a specific short list.
The list to avoid
These accumulate mercury because they’re large, long-lived predators:
- Shark
- Swordfish
- Marlin
- King mackerel
- Bigeye tuna
Limit tuna, both fresh steaks and canned. Canned light tuna is lower in mercury than albacore or “white” tuna; a couple of small servings a week is the usual guidance, and less of the larger species.
Good choices
- Salmon: high in omega-3 and low in mercury, the best all-round option
- Sardines and anchovies, including ikan bilis
- Snapper, threadfin, pomfret, cod, sea bass
- Prawns, squid, crab: all low in mercury, thoroughly cooked
- Smaller mackerel, as distinct from king mackerel
The general principle: smaller and shorter-lived means less mercury. If you can’t identify a fish, that rule handles most decisions.
Raw fish is the bigger issue
Avoid raw and undercooked fish and shellfish: sashimi, raw oysters, ceviche, and raw fish in porridge.
The concern is listeria and parasites, not mercury. Listeria infection is uncommon and can be serious in pregnancy, causing miscarriage, stillbirth or severe illness in a newborn, and pregnancy increases susceptibility to it.
Cooked fish in sushi is fine: unagi, cooked prawn, tamago. It’s the raw items that are out.
Locally specific: yusheng at Chinese New Year contains raw fish. Ask for a portion without it, or toss and skip the fish. And raw fish porridge, where the fish is cooked only by the hot congee, isn’t reliably cooked through. Ask for it fully cooked or choose something else.
Cold-smoked salmon comes with a listeria risk too. Cooking it, in a pasta or on a pizza, resolves that.
Fish oil supplements
- Omega-3 or DHA supplements are a reasonable option if you don’t eat fish, and are commonly included in prenatal ranges.
- Don’t take cod liver oil. It’s high in retinol, the preformed type of vitamin A, which can cause birth defects in high doses. This is the one to check the label for.
- Choose a supplement without vitamin A, and check the whole label, not the front of the pack.
General food safety while you’re at it
- No unpasteurised milk or soft cheeses made from it
- No raw or runny eggs unless pasteurised
- Meat cooked through
- No liver or liver pâté: very high in retinol
- Wash fruit and vegetables
- Avoid food left standing at room temperature, including buffets
- Reheat leftovers thoroughly, or skip them
Frequently asked questions
Can I eat fish while pregnant?
Yes, and you should. Two to three servings a week of low-mercury fish is recommended, not discouraged. Fish supplies omega-3 for brain and eye development, plus protein, iodine and vitamin D.
Which fish should I avoid in pregnancy?
Shark, swordfish, marlin, king mackerel and bigeye tuna, which accumulate mercury as large long-lived predators. Limit tuna generally, both fresh and canned, with canned light tuna being lower in mercury than albacore.
Which fish are safe?
Salmon is the best all-round choice: high in omega-3 and low in mercury. Also sardines and anchovies including ikan bilis, snapper, threadfin, pomfret, cod, sea bass, and prawns, squid and crab when thoroughly cooked. Smaller and shorter-lived means less mercury.
Can I eat sushi while pregnant?
Cooked items are fine: unagi, cooked prawn, tamago. Raw fish isn’t, and the concern there’s listeria and parasites, not mercury. Listeria is uncommon but can be serious in pregnancy, and pregnancy increases susceptibility.
What about yusheng and raw fish porridge?
Yusheng contains raw fish, so ask for a portion without it, or toss and skip the fish. Raw fish porridge relies on the hot congee to cook the fish, which isn’t reliable, so ask for it fully cooked or choose something else.
Should I take a fish oil supplement?
An omega-3 or DHA supplement is reasonable if you don’t eat fish. But don’t take cod liver oil, because it’s high in retinol, which can cause birth defects in high doses. Check the label for vitamin A rather than the front of the pack.
What to remember
Eat fish, two or three servings a week. Avoiding it entirely costs more than it saves.
Skip shark, swordfish, marlin, king mackerel and bigeye tuna, and limit tuna generally. Smaller fish, less mercury.
The bigger risk is raw: no sashimi, no raw oysters, and check the yusheng and the fish porridge.
And if you take a supplement, make sure it isn’t cod liver oil.
Read next
- Prenatal vitamins: what you need and what to avoid
- Caffeine in pregnancy
- Steamed prawns in evaporated milk
This article is general information and not a substitute for medical advice. Check any supplement with your doctor or pharmacist.