Many sushi lovers worry if they can still enjoy their favorite food during pregnancy. This is because they have heard about  the risk to pregnant women due to certain bacteria and increased mercury level. However not all sushi are  uncooked. Most fish also contain some of the necessary nutrients and vitamins needed for the growth and development of the unborn  baby. Eating fish that is well cooked as well as fish low in mercury is a safe way to eat fish.
 

Many of the main fishes used in sushi are high in mercury and should be avoided during pregnancy.

Sushi with high mercury level.

These contain high mercury levels and should be avoided during pregnancy.

• Ahi (yellowfin tuna)
• Aji (horse mackerel)
• Buri (adult yellowtail)
• Hamachi (young yellowtail)
• Inada (very young yellowtail)
• Kanpachi (very young yellowtail)
• Katsuo (bonito)
• Kajiki (swordfish)
• Maguro (bigeye, bluefin or yellowfin tuna)
• Makjiki (blue marlin)
• Meji (young bigeye, bluefin* or yellowfin tuna)
• Saba (mackerel)
• Sawara (spanish mackerel)
• Shiro (albacore tuna)
• Seigo (young sea bass)*
• Suzuki (sea bass)*
• Toro (bigeye, bluefin or yellowfin tuna)

 
Source : American Pregnancy Association

The FDA has identified these fishes as having the highest mercury levels and should be avoided during pregnancy. These are

• tilesfish from the Gulf of Mexico
• sharkfish
• swordfish
• king mackerel

 
Albacore tuna should also be limited to 6 ounces per  week.

Sushi with low mercury level

Eat up to two 6 ounces serving per week.

• Akagai (ark shell)
• Anago (conger eel)
• Aoyagi (round clam)
• Awabi (abalone)
• Ayu (sweetfish)
• Ebi (shrimp)
• Hamaguri (clam)
• Hamo (pike conger; sea eel)
• Hatahata (sandfish)
• Himo (ark shell)
• Hokkigai (surf clam)
• Hotategai (scallop)
• Ika (squid)
• Ikura (salmon roe)
• Kaibashira (shellfish)
• Kani (crab)
• Karei (flatfish)
• Kohada (gizzard shad)
• Masago (smelt egg)
• Masu (trout)
• Mirugai (surf clam)
• Sake (salmon)
• Sayori (halfbeak)
• Shako (mantis shrimp)
• Tai (sea bream)
• Tairagai (razor-shell clam)
• Tako (octopus)
• Tobikko (flying fish egg)
• Torigai (cockle)
• Tsubugai (shellfish)
• Unagi (freshwater eel)
• Uni (sea urchin roe)

 
Source : American Pregnancy Association

Low mercury level means less than 0.29 parts per million mercury level in the flesh of the tested fish.

High mercury level means more than 0.3 parts per million mercury level in the flesh of the tested fish.