Seafood is a great source of protein and omega-3 fatty acids, which are good for your heart. But if you're pregnant, you've probably heard that you should avoid some types of sushi and seafood. The good news is that most types of seafood, including crab and lobster, are safe to eat while you're pregnant. Not only is it safe, eating seafood has a lot of benefits for you and your baby.
Benefits of Eating Seafood While Pregnant
Several studies have shown that the benefits of eating seafood low in mercury while pregnant outweigh the risks. In one study, women who ate less omega-3 fatty acids from seafood had a higher chance of becoming depressed during pregnancy and postpartum. This study concluded that eating seafood during pregnancy could improve pregnant women's mental health.
Another study followed 805 mother-child pairs and asked how much fish the mothers ate during pregnancy. Children of women who ate between 1 and 3 servings of fish weekly while pregnant were tested between the ages of 6 and 12. The children had lower metabolic syndrome scores, which meant they were less likely to get heart disease or diabetes.
Eating fish while you're pregnant may make your baby smarter and more well-behaved. A study of almost 12,000 women showed that children born to women who ate more than 2 servings of fish per week did better on tests of intelligence, behavior, and development than children born to women who ate less fish.
Another study showed that 6-month-old babies whose mothers ate 2 or more servings of low-mercury fish weekly while pregnant had better visual recognition than babies whose mothers didn't. Women who are pregnant should eat 8 to 12 ounces of fish per week to get all of the health benefits.
Seafood to Avoid
Not all seafood is safe to eat when you're pregnant, however. Here are some guidelines about the types of fish and shellfish you should avoid.
Seafood high in mercury. Some fish can be high in mercury, which can harm your baby's developing nervous system. Studies have shown that children born to women who were exposed to mercury during pregnancy could have delayed brain functions. A general rule of thumb is the bigger and older the fish, the more mercury it can contain. It's recommended you avoid these while pregnant:
- Shark
- Marlin
- Orange roughy
- King mackerel
- Bigeye tuna
- Swordfish
- Tilefish
Seafood that is low in mercury includes:
- Light canned tuna
- Anchovies
- Cod
- Catfish
- Herring
- Sardines
- Salmon
- Pollock
- Pacific oysters
- Trout
- Shad
- Talapia
- Shrimp
You should limit albacore tuna to 6 ounces per week.
Raw or undercooked seafood. When you're pregnant, your immune system changes, making you and your baby more susceptible to bacteria and parasites in raw or undercooked seafood. During pregnancy, these illnesses can be worse and can cause miscarriage or preterm delivery.
There are some foodborne illnesses, including Listeria and Toxoplasma gondii that can infect your baby even if you don't feel sick. All seafood should be cooked to at least 145 degrees Fahrenheit. Fish is cooked well when it cannot be seen through and flakes easily. Shrimp, lobster, and scallops should be milky white when cooked. Clams, mussels, and oysters should be cooked until their shells open. You should avoid:
- Sushi
- Sashimi
- Raw oysters
- Raw clams
- Ceviche
You should also avoid refrigerated smoked seafood unless it is canned, shelf-stable, or in a dish that has been cooked to 165 degrees Fahrenheit. This includes many foods labeled:
- Jerky
- Smoked
- Kippered
- Nova-style
- Lox
Seafood listed on fish advisories. Every state and territory in the U.S. issues a warning about fish caught in local waters that may be contaminated with pollutants or mercury. These warnings tell you which fish you can safely eat. The warnings are based on the levels of five toxins that may be present in lakes, rivers, and coastal waters. These include:
- Polychlorinated Biphenyls (PCBs)
- Mercury
- Dichloro-Diphenyl-Trichloroethane (DDT)
- Chlordane
- Dioxins
Eat a Variety of Seafood
Eating a wide variety of seafood helps to limit your exposure to mercury. The Seychelles Child Development Study has followed children in Seychelles, a country of tropical islands in the Indian Ocean, since the mid-1980s. People in Seychelles eat an average of 8 seafood meals a week, which is much more than other places in the world. Being an island nation, they eat a wide variety of seafood.
Since many fish contain mercury, the study is trying to determine if there are any bad effects from eating so many fish. So far, there has been no evidence of abnormal or delayed development in the children, many of whom are now adults.
