During this special time in your life, there are a few beverages and foods you should eliminate or limit to minimize the risk to you and your developing fetus. In most cases, you can easily make substitutions. Here are some dos and donts.

Dont drink beverages containing caffeine. It has a diuretic effect and can dehydrate you, draining your body of nutrients such as potassium, magnesium, zinc and other minerals, B vitaminsespecially thiaminand vitamin C. These beverages can also decrease the absorption of iron and calcium.

Do drink pure filtered or bottled water and herbal teas instead.

Dont consume alcohol. It can cause fetal alcohol syndrome, resulting in mental retardation and facial or other abnormalities. Research has shown that even small levels of alcohol consumed during pregnancy may affect the fetus in damaging ways. Alcohol is not only carried to all organs and tissues, but also to the placenta, where it easily crosses through the membrane separating maternal and fetal blood systems. When a pregnant woman drinks an alcoholic beverage, the concentration of alcohol in her unborn baby's bloodstream is the same level as her own.

Do drink water or seltzer, with a splash of lemon or lime juice if you prefer.

Dont consume raw fish (sushi and sashimi) or raw meat, both of which may contain bacteria that can cause vomiting and diarrhea, which can weaken and dehydrate you. The bacteria could lead to meningitis or pneumonia, or could prove harmful to the baby. Toxoplasmosis, a parasitic disease, can result in a potentially serious intrauterine fetal infection, as can e. coli.

Do cook fish until it's opaque and flakes easily with a fork.

Dont consume large amounts of deep-sea fish, which may have high levels of PCBs and mercury. If exposed, these toxins accumulate in the fishs fatty tissues and eating them can cause fetal brain damage resulting in developmental delays, attention deficit disorders, memory problems and reduced intelligence. Tuna consumption should be limited to seven ounces (about a can) per week. According to the Food and Drug Administration, pregnant women should avoid shark, swordfish, tilefish and king mackerel.

Do feel safe eating fish found in lakes and rivers, such as pink, chum and sockeye salmon. You can safely consume up to 12 ounces each week (about two meals) of other fish such as shellfish, small ocean species or farm-raised fish.

Dont eat river fish, such as trout, salmon, bluefish or striped bass from PCB-contaminated lakes and rivers. If you are unsure of the source, it is best to avoid fish.

Do buy fish from a reputable dealer who knows their sourceand consume farm-raised species. You can also contact the Environmental Protection Agency or your local health department for a list of fish in your region that are safe to consume. Remember that fish is generally a very beneficial food. For example, studies have shown that women who eat fish or use fish-oil supplements decrease the risk of premature and low-weight births.

Dont eat soft cheeses such as blue, Brie, Camembert and feta that may not be adequately pasteurized and could contain bacteria (Listeria) that can cross the placenta and infect the fetus. Listeriosis has been known to cause miscarriage, premature birth, blood poisoning and birth defects.  

Do eat hard and semisoft cheeses such as cheddar, Swiss and mozzarella, and soft, fresh cheeses such as cottage cheese, farmers cheese, cream cheese and mascarpone.

For more on diet and supplements during pregnancy, see A Mother-to-Be Does exersizeyou diet all at once and Vitanutrients for Pregnancy.