Pregnancy and fish: What's safe to eat?
If you're confused about whether it's safe to eat seafood during your pregnancy, you're not alone. Understand the guidelines for pregnancy and fish.
By Mayo Clinic Staff
If you're pregnant, you might feel like you need to become a nutrition expert overnight. After all, what you eat and drink — and what you avoid — influences your baby's development. Some choices are logical, such as eating plenty of fruits and vegetables and eliminating alcohol from your diet. But what about seafood?
Here, Roger W. Harms, M.D., a pregnancy specialist at Mayo Clinic, Rochester, Minn., and medical editor of "Mayo Clinic Guide to a Healthy Pregnancy," offers practical advice about pregnancy and fish.
What's the link between pregnancy and fish?
Seafood can be a great source of protein, iron and zinc — crucial nutrients for your baby's growth and development. In addition, the omega-3 fatty acids in many fish can promote your baby's brain development.
But some types of seafood — particularly large, predatory fish such as shark, swordfish, king mackerel and tilefish — can contain high levels of mercury. Although the mercury in seafood isn't a concern for most adults, special precautions apply if you're pregnant or planning to become pregnant. If you regularly eat fish high in mercury, the substance can accumulate in your bloodstream over time. In turn, too much mercury in your bloodstream could damage your baby's developing brain and nervous system.
How much seafood is recommended?
The Food and Drug Administration (FDA) and the Environmental Protection Agency (EPA) say pregnant women can safely eat up to 12 ounces (340 grams) of seafood a week. Similarly, the 2010 Dietary Guidelines for Americans recommend 8 to 12 ounces of seafood a week for pregnant women — or about two average meals.
Not all researchers agree with these limits, however, citing a study that noted no negative effects for women who ate more seafood than the FDA-approved guidelines.
What's safe to eat?
Eat a variety of seafood that's low in mercury and high in omega-3 fatty acids, such as:
- Atlantic and Pacific mackerel
Other safe choices include shrimp, pollock and catfish. However, limit albacore tuna and tuna steak to no more than 6 ounces (170 grams) a week. Also, be aware that while canned light tuna on average appears safe, some testing has shown that mercury levels can vary from can to can.
Sep. 04, 2014
See more In-depth
- Makrides M, et al. Effect of DHA supplementation during pregnancy on maternal depression and neurodevelopment of young children. JAMA. 2010;304:1675.
- Oken E. Risks and benefits of fish consumption and fish oil supplements during pregnancy. http://www.uptodate.com/home. Accessed March 19, 2013.
- What you need to know about mercury in fish and shellfish. United States Environmental Protection Agency. http://water.epa.gov/scitech/swguidance/fishshellfish/outreach/advice_index.cfm. Accessed March 19, 2013.
- Fresh and frozen seafood: Selecting and serving it safely. U.S. Food and Drug Administration. http://www.fda.gov/food/resourcesforyou/consumers/ucm077331.htm. Accessed March 19, 2013.
- Oken E, et al. Associations of maternal fish intake during pregnancy and breastfeeding duration with attainment of developmental milestones in early childhood: A study from the Danish national birth cohort. American Journal of Clinical Nutrition. 2008;88:789.
- Hibbeln JR, et al. Maternal seafood consumption in pregnancy and neurodevelopmental outcomes in childhood (ALSPAC study): An observational cohort study. The Lancet. 2007;369:578.
- Dunstan JA, et al. Cognitive assessment of children at age 2 1/2 years after maternal fish oil supplementation in pregnancy: A randomized controlled trial. Archives of Childhood Diseases: Fetal and Neonatal Edition. 2008;93:F45.
- Position of the American Dietetic Association: Nutrition and lifestyle for a healthy pregnancy outcome. Journal of the American Dietetic Association. 2008;108:553.
- Dietary Guidelines for Americans, 2010. U.S. Department of Health and Human Services. http://www.cnpp.usda.gov/Publications/DietaryGuidelines/2010/PolicyDoc/PolicyDoc.pdf. Accessed March 19, 2013.
- Position of the American Dietetic Association: Vegetarian diets. Journal of the American Dietetic Association. 2009;109:1266.
- Your Pregnancy and Childbirth: Month to Month. 5th ed. Washington, D.C.: American College of Obstetricians and Gynecologists; 2010:85.
- Kris-Etherton PM, et al. Polyunsaturated fatty acids in the food chain in the United States. The American Journal of Clinical Nutrition. 2000;71:179S.
- Fish facts. The National Women's Health Information Center. http://www.womenshealth.gov/publications/our-publications/fish-facts.pdf. Accessed March 19, 2013.
- Strain JJ, et al. Maternal PUFA status but not prenatal methylmercury exposure is associated with children's language functions at age five in the Seychelles. The Journal of Nutrition. 2012;142:1943.
- Koletzko B, et al. Dietary fat intakes for pregnant and lactating women. British Journal of Nutrition. 2007;98:873.
- USDA National Nutrient Database for Standard Reference, Release 25. U.S. Department of Agriculture, Agricultural Research Service. http://ndb.nal.usda.gov. Accessed April 16, 2013.
- Zeratsky KA (expert opinion). Mayo Clinic, Rochester, Minn. April 15, 2013.