I think we can eat most fish. Some research I done.
Do not eat Shark, Swordfish, King Mackerel, or Tilefish because they contain high levels of mercury.
Fish including sardines, light tuna and salmon are rich in omega-3 fatty acids -- components of fat known to help brain development.
The current recommended amount for pregnant women is no more than two portions of oily fish per week. Oily fish are like salmon, trout or herring, etc.
Other than that, i think we can eat as much fish as we like.