Omega-3 Fatty Acids and Pregnancy: Benefits for Mother and Baby

Omega-3 fatty acids play a critical role in supporting a healthy pregnancy and optimal fetal development. Research consistently shows that adequate intake of omega-3s—particularly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)—offers benefits for both maternal health and infant outcomes, from reducing pregnancy complications to supporting brain and visual development.

Why Omega-3s Matter During Pregnancy

During pregnancy, omega-3 fatty acids are actively transferred across the placenta to support fetal growth and development. DHA, in particular, is a key structural component of the cerebral cortex and retina, making it essential for early neurological and visual development. Adequate maternal intake has been associated with improved cognitive performance, fine motor skills, and communication abilities in children.

At the same time, pregnancy places increased demands on the mother’s omega-3 stores. The fetus relies on maternal DHA and EPA for nervous system development, and after birth, omega-3s continue to be used in the production of breast milk. With each subsequent pregnancy, maternal depletion may increase if dietary intake is insufficient.

Pregnancy Outcomes and Maternal Health

Higher intake of EPA and DHA during pregnancy has been linked to several positive outcomes:

• Reduced risk of preterm labor and delivery, likely due to the anti-inflammatory properties of omega-3s and their role in supporting placental function

• Lower risk of preeclampsia, though research in this area continues to evolve

• Potential increases in birth weight, supporting healthier fetal growth

• Support for maternal mental health, as omega-3 deficiency has been associated with an increased risk of depression, including postpartum mood disorders

These findings are particularly important in the context of modern diets, which are often low in omega-3 fatty acids. Western dietary patterns tend to emphasize omega-6 fats while providing insufficient EPA and DHA, compounding the risk of deficiency during pregnancy.

Omega-3s and Infant Development

DHA is uniquely important for the developing brain, eyes, and central nervous system. Studies suggest that children whose mothers consumed higher levels of omega-3s during pregnancy perform better on measures of intelligence, vision, and early developmental milestones. There is also evidence that adequate omega-3 intake may reduce the risk of allergies in infancy.

EPA, while less directly involved in structural brain development, supports cardiovascular health, immune function, and regulation of inflammation—benefits that indirectly contribute to a healthier pregnancy environment.

Dietary Sources of Omega-3 Fatty Acids

Omega-3s come in several forms:

• Alpha-linolenic acid (ALA), found in plant sources such as flaxseed, walnuts, canola oil, and other vegetable oils

• EPA and DHA, found primarily in animal tissues, especially fatty fish

While the body can convert ALA into DHA and EPA, this conversion is limited and inefficient. For this reason, direct sources of EPA and DHA are especially important during pregnancy.

The best natural sources used to include cold-water fatty fish such as salmon, sardines, anchovies, herring, and mackerel. However, concerns about mercury and other contaminants are valid, especially for pregnant women. Older guidance generally recommended consuming fish two to three times per week, prioritizing smaller fish (such as sardines and anchovies) and limiting larger species like tuna. The newest literature suggests just the opposite, given the level of contamination in most fish currently.

Supplements and Safety Considerations

Because meeting increased DHA and EPA needs through diet alone can be challenging, especially with fish-consumption limits, many pregnant women turn to omega-3 supplements. Highly purified fish oil supplements can provide a safe and reliable source of EPA and DHA while minimizing exposure to contaminants such as mercury. Supplement use should always be discussed with a healthcare professional to ensure appropriate dosing and quality.

What the Evidence Still Debates

While the benefits of omega-3s for fetal neurological and visual development are well supported, research on their role in preventing specific pregnancy complications—such as preeclampsia or gestational diabetes—remains mixed. Evidence regarding omega-3s and postpartum depression is also promising but not yet definitive. Ongoing research continues to refine intake recommendations and clarify these relationships.

Takeaway

• Omega-3 fatty acids, especially DHA and EPA, are essential nutrients during pregnancy.
• Widespread dietary deficiency of omega-3s, pregnant
• “Safe” fish consumption  for achieving adequate DHA and EPA is now questionable
• Supplement with a high-quality, third party tested product (oxidation and toxic metals) that contains a quality anti-oxidant
• Take omega 3’s with food that contains fats (ex. avocados to salad dressings to meats)
• If you eat fish, avoid farmed and only partake in the smaller species

Yakah W, Haas DM, Grobman WA, Levine LD, Reddy UM, Silver R, Vacher C-M, Wapner RJ, Penn AA and Firestein MR (2026) Omega-3 supplementation in addition to prenatal vitamins during pregnancy is associated with lower rates of preterm birth and small for gestational age. Front. Nutr. 12:1693844. doi: 10.3389/fnut.2025.1693844