To eat fish or not to eat fish: Pregnant, breastfeeding women ask the question

In June, following a survey that found that the majority of pregnant women do not eat much fish and thus may have inadequate intake of certain omega 3 fatty acids, the Food and Drug Administration (FDA) and the Environmental Protection Agency (EPA) issued updated advice on fish consumption for pregnant and breastfeeding women.

Toward clarifying this complicated issue, Katharine D. Wenstrom, MD, director of the Division of Maternal-Fetal Medicine at Women & Infants Hospital of Rhode Island, co-director of the hospital's Integrated Program for High-Risk Pregnancy, and a professor of obstetrics and gynecology at The Warren Alpert Medical School of Brown University, has published a Viewpoint in the November 2014 issue of American Journal of Obstetrics & Gynecology entitled, "The FDA's new advice on fish: it's complicated."

"This is a complicated issue, as fish high in omega 3 acids have incredible health benefits for a developing fetus and a growing baby, but some fish also pose significant risk," said Dr. Wenstrom. "My colleagues often tell me that their patients ask, 'Do I eat fish, or not? And if so, which fish is safe to eat and which should I avoid?'. In balancing the risks and nutritional benefits of different types of fish, pregnant and breastfeeding women should eat at least eight ounces and up to 12 ounces of fish per week, including salmon, pollack, squid, sardines and oysters, which offer the highest levels of eicosapentaenoic acid (EPA) and ducosahexaenoic acid (DHA), with the lowest levels of mercury."

Omega 3 acids EPA and DHA, which are found in very high levels in some fish, are essential components of membranes in all cells of the body and are vital for normal development of the brain and retinal tissues and for maintenance of normal neurotransmission and connectivity. Maternal ingestion of adequate quantities of EPA and DHA has been associated with better childhood IQ scores, fine motor coordination, and communication and social skills, as well as other benefits. Unfortunately, taking omega 3 fatty acid or fish oil supplements does not seem to have the same beneficial effects of eating fish.

Some fish that offer high levels of omega 3 acids are also dangerously high in mercury and should be avoided or at least limited in consumption, especially during pregnancy and while breastfeeding. The FDA specifically advised against pregnant and breastfeeding women eating shark, tilefish, swordfish and king mackerel because they have the highest levels of mercury. They also recommended limiting consumption of albacore tuna to six ounces per week.