Pregnancy and Fish

While fish is packed with proteins, vitamins and minerals that are important for the growth of your baby, there are some types you should avoid or limit.

Include low-mercury fish in your diet twice a week. A cohort study published in October 2005 by the Harvard Medical School found that babies from mothers with higher low-mercury-fish consumption during second trimester have better scores in mental development. Low-mercury fish include shrimp, crab, cod, clams, scallops, canned light tuna, canned salmon, pollock, and catfish, among others.

One of the twice-per-week portions of fish should be an oil rich type, such as salmon, trout or sardines. They are rich in omega-3 fats, which are essential for the development of a baby's brain, eyes and nerves, but they may also contain pollutants that can damage a fetus, so stick to the recommended amount.

Steer clear of deep-sea fish, such as shark, swordfish and marlin, as these can be high in mercury. Eat no more than 140g cooked fresh tuna steaks (or four small cans of tuna) in a week, and avoid raw shellfish, like oysters, too, as they may contain bacteria that could lead to food poisoning.

It's fine to eat cooked shellfish, such as mussels and prawns, as long as they are part of a hot meal and are cooked thoroughly.