Fish is a good source of high-quality protein, vitamins , and minerals .
However, there have been questions raised regarding the effects on the fetus of methyl mercury in fish consumed during pregnancy. Fish absorb methyl mercury from water as it passes over their gills and as they feed on aquatic organisms. Larger predator fish are exposed to higher levels of methyl mercury from their prey. Methyl mercury binds tightly to the proteins in fish tissue, including muscle, and cooking does not appreciably reduce the methyl mercury content of the fish. Pregnant women and women of childbearing age who may become pregnant, are advised by the FDA to limit their consumption of shark and swordfish to no more than once a month.