Mercury is one element that occurs in nature naturally. But this mercury is also released into several water bodies in the name of industrial waste. As it enters the ocean and the sea many bacteria transforms it into methyl mercury or di methyl mercury. The methyl mercury is taken by the fish from the plants and organisms they eat. As methyl mercury can have very bad effects on the growth of the fetus. As sea food contains high amount of methyl mercury it is dangerous to have food during pregnancy.

Some fish that completely needs to be avoided are shark, swordfish, king mackerel, tilefish, tuna steak, Spanish mackerel, marlin, grouper, large and small mouth bass, walleye, northern pike, lake whitefish, salmon from the great lakes, bowfin, gar, toxic species like puffer fish, blow fish, and sea squab. As these fish are at the top of the food chain they are the ones that carry the highest level of mercury.

Fish that contain lowest level of mercury are:

• Shrimp
• Canned salmon
• Canned tuna in oil
• Herrings
• Sardines
• Pollock
• Catfish
• And hake

Reasons why eating fish during pregnancy is beneficial to the fetus are:

• Fish are rich in proteins
• Rich in vitamins
• And also fish are rich in omega 3 fatty acids which help in the growth of the baby. These fatty acids are fish oil which protects the baby from heart diseases or stroke. Thus fish is not completely harmful for the unborn babies.

How much fish eating is safe for a pregnant woman?

• 2 to 3 servings of fish per week.
• But it depends on the kind of fish that is chosen as it is advisable to choose those fish that are low in mercury content.
• Some of the fish that are safe to be consumed twice a week are Salmon in all forms except from the Great lakes, framed trout, sardines, herrings, pilchards, flounder and sole, farmed cat fish, stripped bass and tilapia, cod, haddock, mahi mahi, perch, crab, scallops, clams, oysters, mussels and cray fish.