Omega-3 Fatty Acids During Pregnancy

During pregnancy, your baby gets most of their food from the foods you eat and vitamins you take. Omega-3 fatty acids (omega 3s) are an important family of building blocks needed during pregnancy and breastfeeding. The two most important omega-3s are DHA and EPA. Our bodies cannot make these fatty acids so we have to get them from food.

Omega-3s are important to health. They can lower blood pressure and reduce heart diseases and other health problems. Omega-3s improve your baby's eye and brain growth and early development. Taking in enough omega-3s can lower your baby's chances of being born to soon, or getting asthma and other allergic conditions. They also may lower your risk of depression after you have your baby (postpartum depression).

Only a few foods contain omega-3s. Fatty fish like salmon, sardines, and trout are the best sources. Omega-3s are also now added to certain foods (fortified) like some brands of eggs, milk, juice, and yogurt. Walnuts, flaxseed, chia seeds, seaweed and grass-fed beef all have DHA, just in lower amounts.

Because of mercury contamination of our oceans, rivers and lakes, almost all fish contain some mercury. Some fish contain too much mercury. Some fish may also have PCBs (polychlorinated biphenyls) and dioxin from industrial pollution. High amounts of mercury and PCBs in your body can cause problems with your baby's brain growth, so fish with high levels of these toxins should not be eaten during pregnancy. Check local advisories on the safety of fish from local waters. Fish advisories are available from your local health department and online from state agencies. The health benefits of eating low mercury fish during pregnancy outweigh the risks, so DO eat safe fish during pregnancy and while you are breastfeeding your baby.

Choose fish low in mercury. Remove skin and fat before cooking. Baking, broiling, steaming, or grilling fish lets the fat drain away and reduces PCBs in fish. Do not eat raw fish or shellfish.

Pregnant women and women who are breastfeeding should get about 200–300 mg of omega-3s per day. Since omega-3s stay in the body for a few days, eating 2 to 3 servings of fatty fish per week can give you the 200–300 mg per day needed. One serving is a 4 ounce portion of cooked fish. If you do not eat fish, or do not want to eat it every week, you can get fish oil as a pill or liquid you can swallow. Purified fish oil in pills or liquid form have all PCBs and dioxin removed. Read the label carefully to make sure there are at least 200 mg of omega-3s. Fish oil pills generally do not have side effects. Some women do say they have a fishy aftertaste with burping. There are other foods that contain DHA. If you prefer get your DHA through these sources, you will need to eat more of them or buy food that has been fortified to get the amount of DHA you need. Eating less fried and processed foods in your diet will help your body's ability to use the omega-3s you are taking in. Fish liver oils like cod liver oil should be avoided in pregnancy because they can cause dangerous levels of Vitamin A in your body.

Reviewed from FDA website 8-25-2025; AdviceAboutEatingFish-MainPDF-2021-10-26-1025.pdf

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Approved August 2025. This handout replaces “Omega-3 Fatty Acids During Pregnancy” published in Volume 55, Issue 6, November/December 2010