Crawfish and Crayfish
Crawfish (also called crayfish) are safe during pregnancy when thoroughly cooked, with the same safety profile as other cooked shellfish like prawns or crab.
Cross-checked against NHS guidance
Crawfish and crayfish are two names for the same small freshwater crustacean — 'crawfish' is the more common term in the US (especially in Cajun cooking, like a crawfish boil), while 'crayfish' is more typical in the UK. Either way, they're safe to eat during pregnancy as long as they're cooked thoroughly, following the same rule as prawns, crab, and lobster. They should be cooked until the shell turns bright red/pink and the flesh is opaque, and any that don't open or cook properly in a batch should be discarded. Crawfish are low in mercury, similar to other shellfish, so they don't carry the portion restrictions that apply to large predatory fish. As with any shellfish, buy from a reputable source and avoid any that have been sitting out at room temperature, such as at a buffet.
What to be aware of
- Cook crawfish/crayfish thoroughly — never eat them raw.
- Buy from a reputable source and check they've been stored properly chilled.
- Avoid crawfish that have been sitting out at room temperature, such as at a boil or buffet left unrefrigerated.
- A traditional Cajun crawfish boil is fine as long as the crawfish are fully cooked — just be mindful of the heavily spiced, salty cooking liquid in large quantities.
US guidance
The FDA lists crawfish among its 'best choices' low-mercury seafood, with the standard advice to ensure thorough cooking.