Eating fish during pregnancy often raises questions about safety and nutritional value. Despite concerns about contaminants, medical guidelines emphasize fish consumption for maternal health and fetal development. This article provides guidance on safely incorporating fish into a pregnancy diet.
Key Nutritional Benefits
Fish offers a range of nutrients important for a healthy pregnancy. Omega-3 fatty acids, specifically DHA and EPA, play a significant role in fetal brain and eye development. These fatty acids are essential because the body cannot produce them in adequate amounts, making dietary intake important. Sufficient maternal omega-3 intake can contribute to improved neurocognitive development in children, including better verbal, motor, and memory skills.
Fish also provides lean protein for the growth of the baby’s cells, tissues, and organs. It supplies vitamin D, which supports both maternal and fetal bone health. Additionally, fish contains iodine for thyroid function, and vitamin B12, which aids in red blood cell formation.
Addressing Potential Risks
While fish offers nutritional advantages, concerns about potential risks, primarily mercury contamination, exist. Mercury is a naturally occurring element that transforms into methylmercury in aquatic environments. Fish absorb methylmercury from their environment and by consuming smaller fish.
Methylmercury is a neurotoxin that, in high quantities, can damage a baby’s developing brain and nervous system. Exposure to elevated levels during pregnancy can lead to issues such as learning disabilities or problems with hearing and vision. Larger, longer-lived, and predatory fish tend to have higher concentrations of mercury because it accumulates in their tissues over time. Mercury remains the primary concern for pregnant individuals.
Smart Fish Choices for Pregnancy
Incorporating low-mercury, nutrient-rich fish into a pregnancy diet is recommended. The FDA and EPA suggest pregnant individuals consume 8 to 12 ounces (about two to three servings) of low-mercury fish per week. Good choices include salmon, high in DHA and protein, supporting neurological and visual development.
Other safe and nutritious options include anchovies, herring, sardines, freshwater trout, and Pacific mackerel. Shrimp, pollock, tilapia, cod, and catfish are also good choices. Canned light tuna (skipjack) is another convenient low-mercury option that provides DHA, protein, and vitamin B12, supporting brain, eye, and immune system development. Choose a variety of these low-mercury fish throughout the week to maximize nutritional benefits.
Fish to Avoid or Limit
To minimize mercury exposure, certain fish should be avoided or consumed in very limited quantities during pregnancy. Fish known to have high levels of methylmercury include shark, swordfish, king mackerel, and tilefish. These large, predatory species accumulate more mercury due to their position in the food chain and longer lifespans.
The FDA and EPA specifically advise against eating these varieties:
- King mackerel
- Marlin
- Orange roughy
- Shark
- Swordfish
- Tilefish from the Gulf of Mexico
- Bigeye tuna
For canned white (albacore) tuna and tuna steaks, limit consumption to no more than 6 ounces per week due to their higher mercury content compared to canned light tuna. If eating fish caught from local waters, check local advisories for mercury levels. Without specific advisories, limit consumption to one serving per week, avoiding other fish that week.
Safe Handling and Cooking
Proper handling and thorough cooking of fish are important to prevent foodborne illnesses during pregnancy. All fish and shellfish should be cooked to an internal temperature of 145 degrees Fahrenheit (63 degrees Celsius). Fish is adequately cooked when its flesh becomes opaque throughout and separates easily with a fork. Shellfish like shrimp and lobster turn pearly and milky white, while clams, mussels, and oysters are done when their shells open.
Raw or undercooked fish and shellfish, including sushi, sashimi, and ceviche, should be avoided entirely during pregnancy. These can harbor harmful bacteria or parasites that pose a risk to both the pregnant individual and the developing baby. Use separate cutting boards for fish preparation and wash hands and cooking surfaces thoroughly to prevent cross-contamination.