Women may feel that eating fish during pregnancy is risky because of years of concerning messaging about mercury contamination in certain species. But fish—especially oily fish—may be the best dietary source of the omega-3 fatty acids crucial to a baby’s development. The right amounts of safe fish are an important part of a pregnant woman’s diet.
The study looked at fish consumption among 10,800 pregnant women and omega-3 supplement intake among 12,646 pregnant women from across the United States who were participating in a program called Environmental Influences on Child Health Outcomes.
Nearly 25 percent of the participants reported not eating fish or eating it less often than once per month, and only 16 percent took omega-3 supplements. Older mothers with higher education and income and those who were non-Hispanic white or Asian were most likely to take supplements. However, fish consumption was higher among women with racial or ethnic identities other than non-Hispanic white and among those who used tobacco and nicotine products.
Women’s fish consumption and omega-3 supplementation during pregnancy have been declining over the past decades, the investigators noted. They suggested that this phenomenon was “likely in response to federal advisories about mercury in fish since 2001.”
They proposed improved messaging to pregnant women regarding the importance of omega-3s.
Why Is Omega-3 Important During Pregnancy?
Docosahexaenoic acid (DHA) and eicosatetraenoic acid (EPA), two omega-3 fatty acids found in oily fish, are important for supporting a healthy pregnancy, the American Pregnancy Association noted on its website, and these fatty acids may reduce the risks of pre-term labor and postpartum depression.For lactating women, adequate intake of the healthy omega-3s found in fish is linked to outcomes including better infant psychomotor development and a reduced risk of infant allergies, according to the association.
Fear of Fish: Mixed Mercury Messaging
Since 1994, the Food and Drug Administration’s (FDA’s) advice regarding fish consumption has recommended that pregnant women avoid eating shark and swordfish. (Larger predatory fish such as these accumulate more mercury in their bodies than smaller species do.)In 2001, tilefish and king mackerel were added to this list, and the FDA issued an advisory recommending that pregnant women avoid these fish because of the possibility of mercury contamination.
“We can conclude that the issuance did not influence women on a national level to decrease their fish consumption,” the report reads.
However, Dr. Stephen Ostroff, former FDA acting chief scientist, said in a 2014 statement updating FDA advice to pregnant women, “For years many women have limited or avoided eating fish during pregnancy or feeding fish to their young children.”
The statement encouraged pregnant or breastfeeding women to consume eight to 12 ounces of various low-mercury fish per week for its nutritional benefits.
Weighing Risks and Benefits
Mercury advisories have not effectively informed consumers and have caused confusion, according to the website Mercury Facts and Fish, part of the Mercury Policy Project.“Most people are not aware of specific government advice on mercury; those who know that mercury is a concern generally cannot say which fish they should avoid to reduce mercury exposure, or which fish are low in mercury and should be chosen often,” it reads.
“There is some evidence that pregnant women find the advice confusing and prefer to give up eating fish altogether rather than take the risk of harm,” the investigators said. “There is general agreement that pregnant women should eat at least two portions of fish per week, but this message is not always clear and prominent.”
“When mothers regularly consume fish during pregnancy, their children are likely to have improved neurodevelopment compared to children of non-fish eaters, despite their exposure to methylmercury,” the authors wrote.
What Fish Are Safest to Eat? Are Supplements a Good Source?
The March of Dimes echoes the FDA in recommending pregnant women eat eight to 12 ounces a week of low-mercury fish, including:- Shrimp
- Salmon
- Pollock
- Catfish
- Canned light tuna
- Shark
- Swordfish
- King mackerel
- Tilefish
- Chia seeds
- Edamame
- Flaxseeds
- Hemp seeds
- Kidney beans
- Seaweed
- Walnuts
- Wheat germ
Supplements should have at least 200 mg of omega-3s, the group stated, and pregnant women should avoid fish liver oils such as cod liver oil because they can cause dangerous levels of vitamin A in the body.
