“Is There Anything I Shouldn’t Eat or Drink?”
* Smoking cigarettes and using drugs and alcohol are already bad for your health, but when you are pregnant, using any of these substances can affect your baby too.
* Smoking cigarettes while pregnant can cause your
baby to be very small at birth, and even prevent your
baby’s lungs from developing properly.
* Drinking any amount of alcohol during pregnancy is unsafe.  Drinking while pregnant can cause mental retardation and even fetal alcohol syndrome.
Click here for more information:    
Some foods may be harmful during pregnancy, so it is best to avoid eating:
- raw seafood or rare beef or poultry
- fish with mercury, such as - shark, swordfish, king mackerel, fresh tuna, sea bass, and tilefish. Canned, chunk light tuna generally has less amounts of mercury than other tuna, but still should only be eaten in small amounts.
- raw eggs or shellfish
- soft cheeses, such as - brie, camembert, Roquefort, feta, gorgonzola and Mexican style cheeses that include queso blanco and queso fresco. Soft non-imported cheeses made with pasteurized milk are safe to eat.
-caffeine - Avoid caffeine during the first trimester to reduce the likelihood of a miscarriage. As a general rule, in later stages of your pregnancy caffeine should be limited to fewer than 300 mg, or two cups of coffee per day.