Fish and shellfish advice for pregnant or breastfeeding women

Sep 28, 2007 at 9:29 p.m. ET

Fish and shellfish can be an important part of a balanced diet. It is a good source of high quality protein and other nutrients and is low in fat. The US Food and Drug Administration and the Environmental Protection Agency are advising pregnant women and nursing mothers to eat the types and amounts of fish and shellfish that are safe to prevent harm to the development of their baby or young child.

There are health benefits of eating fish but to avoid any developmental problems from mercury in fish, mothers should follow these guidelines.

To protect your baby follow these 3 rules:

  • 1. Do not eat shark, swordfish, king mackerel, or tilefish because they contain high levels of mercury
  • 2. Levels of mercury in other fish can vary. You can safely eat up to 12 ounces (2 to 3 meals) of other purchased fish and shellfish a week. Mix up the types of fish and shellfish you eat and do not eat the same type of fish and shellfish more than once a week.
  • 3. Check local advisories about the safety of fish caught by family and friends in your local rivers and streams. If no advice is available, you can safely eat up to 6 ounces (one meal) per week of fish you catch from local waters, but don't consume any other fish during that week.

Follow these same rules when feeding fish and shellfish to your young child, but the serving sizes should be smaller

Frequently asked questions about mercury in fish
1. But I thought fish was good for me when I am pregnant?
It is. Fish and other seafood long have been considered to be good sources of protein with the added advantage of being low in saturated fat and high in healthy omega-3 fatty acids. However, scientists have learned that shark, swordfish, king mackerel and tilefish contain levels of mercury in them that may harm your unborn child. This is why FDA and EPA are advising you to avoid these fish. By eating other types of fish in moderation you will get the health benefits of fish.

2. What about tuna?
Tuna is one of the most frequently consumed fish in the United States. Mercury levels in tuna vary. Tuna steaks and canned albacore tuna generally contain higher levels of mercury than canned light tuna. You can safely include tuna as part of your weekly fish consumption.

3. Is there methylmercury in all fish?
Nearly all fish contain traces of methylmercury. However, larger fish that have lived longer have the highest levels of methylmercury because they've had more time to accumulate it. These large fish (swordfish, shark, king mackerel and tilefish) pose the greatest risk to pregnant women. Other types of fish are safe to eat in the amounts recommended by FDA and EPA If you want more information about the levels in various types of fish see the FDA food safety web site or the EPA web site at

4. I'm not pregnant, so why should I be concerned about methylmercury?
If you regularly eat types of fish that are high in methylmercury, it can accumulate in your blood stream over time. Methylmercury is removed from the body naturally, but it may take over a year for the levels to drop significantly. Thus, it may be present in a woman even before she becomes pregnant. This is one of the reasons why women who are trying to become pregnant should also avoid eating certain types of fish.

5. Why do I need to get local advice for locally caught fish?
Some kinds of fish and shellfish caught in your local waters may have higher or much lower than average levels of mercury. This depends on the levels of mercury in the water in which the fish are caught. Those fish with lower levels may be safely eaten more frequently and in larger amounts.

6. How can learn about local advisories?
Before you go fishing, check your Fishing Regulations Booklet for information about local advisories. You can also contact your local health department for information about local advisories. See below for state and tribal contact information. 7. What is mercury?
Mercury occurs naturally in the environment and can also be released into the air through industrial pollution. It falls from the air and can accumulate in streams and oceans and is turned into methylmercury in the water. It is this type of mercury that is harmful to your baby. Fish absorb the methylmercury as they feed in these waters and so it may build up in the fish. It builds up more in some types of fish than others, depending on what the fish eat, which is why the levels in the fish vary.

Note: If you have questions or think you've been exposed to large amounts of methylmercury, see your doctor or health care provider immediately. For further information about the risks of mercury in fish and shellfish call the US Food and Drug Administration's food information line toll-free at (888) SAFEFOOD or visit FDA's Food Safety web site