If you’re a seafood lover, you might be confused about which kinds of fish and shellfish are safe to eat during pregnancy.

It’s true that certain types of sushi are a big no-no while you’re expecting. But that doesn’t mean you’re banned from lobster bars or crab feasts for the next nine months.

Doctors want you to consume seafood. It’s a great source of protein, vitamins A and D, and essential omega-3 fatty acids. It’s great for baby’s brain and eye development. It might even help combat depression during pregnancy and postpartum.

So go ahead and enjoy that clam chowder or seared flounder filet. Just keep the following tips in mind.

Raw or undercooked fish and shellfish are more likely to contain harmful parasites and bacteria. Eating these could lead to foodborne illnesses like listeriosis, toxoplasmosis, and salmonella.

Pregnancy changes your immune system. This makes it more difficult for your body to fight off the foodborne microorganisms that cause these illnesses.

Your baby’s developing immune system isn’t advanced enough to fend for itself. Consuming raw or undercooked seafood could result in birth defects or miscarriage.

Most fish contain mercury, which may be harmful to your baby’s evolving nervous system in large amounts. The U.S. Food and Drug Administration (FDA) recommends steering clear of:

  • swordfish
  • king mackerel
  • tilefish
  • shark
  • marlin

Instead, opt for lower mercury options like shrimp, salmon, clams, tilapia, and catfish.

The FDA also recommends canned light tuna, saying it contains less mercury than albacore (white) tuna. But you might want to limit your canned tuna intake to 6 ounces each week or less. A 2011 Consumer Reports review found that canned tuna is actually the most common mercury source in the American diet.

Mercury can accumulate in the bloodstream over time, so it’s also important to monitor your intake before you become pregnant.

If you’re pregnant or planning to become pregnant and think you’ve been exposed to mercury, see your doctor immediately.

Most seafood contains some amount of mercury. But by eating a wide variety of fish and shellfish, you can reduce your overall mercury consumption.

During pregnancy, eating up to 12 ounces of seafood each week is considered safe. Keep in mind that a typical serving size for fish is 3 to 6 ounces.

One study published in The Lancet found no negative effects for pregnant women in the Seychelles who ate more than 12 ounces each week. In fact, the women in the study ate up to 10 times more fish than the average American. The study noted that these women ate a wide variety of ocean life.

Seafood can be safe during pregnancy, but only if it’s prepared correctly. So give yourself permission to be picky.

Undercooked seafood can be just as risky as the raw version. Most of the harmful parasites and bacteria are killed off during the cooking process. So make sure your food is piping hot. Use a cooking thermometer to be sure everything’s been cooked thoroughly. If your restaurant meal is served lukewarm, send it back.

Whether you’re cooking, eating out, or ordering for delivery, take care that your meal isn’t prepared near or on the same surface as raw fish or meat. This will decrease the likelihood of any parasites or bacteria being transferred onto your food.

Refrigerated smoked seafood is off-limits during pregnancy. So turn down anything marked “nova-style,” “lox,” “kippered,” smoked,” or “jerky.”

Also be wary of any fish caught in local waters, as it could contain contaminants. Consult guidelines and look for local fish advisories before eating locally caught fish. If you’re uncertain of the safety of fish you’ve already eaten, forego seafood for the rest of the week and call your doctor.

How your food is handled, prepared, and stored is also important for safety. Here are some tips for maximizing the safety and longevity of your seafood:

  • Wash all cutting boards, knives, and food prep areas with hot, soapy water after handling raw seafood.
  • Use separate knives and cutting boards for raw seafood.
  • Fish should be cooked until it flakes and appears opaque; lobster, shrimp, and scallops until milky white; and clams, mussels, and oysters until the shells pop open.
  • Store all leftover and perishable foods in an airtight container in the refrigerator at 40˚F (4 ˚C) degrees or lower, or in the freezer at 0˚F (–17˚C).
  • Discard any food that’s been left out at room temperature for more than two hours.
  • Toss out any perishable, precooked, or leftover food after four days.
  • Wash your hands thoroughly before and after handling food.

Eating a variety of fish and shellfish is important for your overall health, especially during pregnancy. Aim for at least 8 ounces of pregnancy-safe seafood per week.

If you’re unsure what you should be eating or how much, ask your doctor.