Docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) are long-chain omega-3 polyunsaturated fatty acids that the body cannot efficiently produce, making them essential nutrients obtained through diet or supplementation. During pregnancy, the need for these fatty acids increases significantly because the mother is the sole supplier to the developing fetus via the placenta. Adequate intake supports both maternal health and the baby’s rapid growth. Consistent daily consumption is important, as the transfer of these fatty acids can deplete the mother’s own stores with each pregnancy.
The Role of DHA and EPA in Fetal Development
DHA and EPA play a structural role in the developing fetus, particularly in the formation of the central nervous system and the visual system. DHA is a major structural component of the brain and the retina, accounting for a large percentage of the fatty acids in cell membranes. This fatty acid supports optimal development of cognitive function and visual acuity by being involved in neural function and neurotransmitter metabolism.
The accumulation of DHA in the fetal brain accelerates dramatically during the second half of pregnancy, accruing an estimated 50 to 70 milligrams per day in the third trimester. Maternal intake directly influences fetal concentrations, since the body cannot efficiently convert plant-based omega-3 (ALA) into active DHA and EPA. These fatty acids support neurogenesis and synaptic plasticity, foundational processes for the baby’s future development. Adequate maternal omega-3 intake may also reduce the risk of early preterm birth and support the mother’s mood, potentially lowering the risk of postpartum depression.
Official Recommended Daily Intake During Pregnancy
Most health organizations advise that pregnant women consume at least 200 milligrams of DHA per day. Some guidelines suggest a combined intake of 250 to 300 milligrams per day of total omega-3s (DHA plus EPA), with a minimum of 200 milligrams being DHA. EPA is also important, supporting growth and providing anti-inflammatory benefits to both mother and baby.
For women starting pregnancy with low omega-3 status, a healthcare provider may suggest a higher supplemental dose. Evidence suggests that higher daily doses, such as 1,000 milligrams of DHA, can significantly reduce the risk of early preterm birth, particularly for those with low baseline intake.
The American College of Obstetricians and Gynecologists (ACOG) recommends an additional 100 to 200 milligrams of DHA daily, supplementing the 250 milligrams per day of DHA plus EPA recommended for all adults. The total combined intake often falls in the range of 350 to 450 milligrams per day during pregnancy. Pregnant individuals should discuss their diet and health with a healthcare provider to determine the appropriate daily target.
Obtaining Omega-3s: Diet Versus Supplementation
The most direct way to obtain DHA and EPA is through marine sources, primarily fatty fish and seafood. Consuming two servings per week of low-mercury fish is often recommended to meet the minimum intake, providing approximately 200 milligrams of DHA daily. Safe, low-mercury options include salmon, sardines, herring, anchovies, and farmed oysters.
Concerns about mercury and other environmental contaminants can make meeting this target through diet challenging. Larger, longer-lived fish, such as swordfish, shark, and king mackerel, accumulate higher levels of mercury and should be avoided during pregnancy. For those who do not eat fish or are concerned about contaminants, supplementation is a practical alternative.
Supplements are a reliable and mercury-safe source of omega-3s; many prenatal vitamins now include 200 to 300 milligrams of DHA. While fish oil capsules are common, plant-based algal oil supplements are also available, providing a direct source of DHA without the risk of ocean-borne contaminants. When selecting a supplement, check the label to ensure it provides at least the recommended minimum of DHA and has been third-party tested for purity and potency.