Docosahexaenoic Acid (DHA) is a long-chain omega-3 fatty acid frequently discussed in prenatal nutrition. As a polyunsaturated fatty acid, it is a foundational component of cell membranes throughout the body. Since the human body is not efficient at producing DHA, expectant mothers must obtain adequate amounts through diet or supplementation. This external intake is important during pregnancy to ensure both maternal health and optimal fetal development.
The Essential Role of DHA in Fetal Development
DHA is one of the most abundant fatty acids found in the human brain and retina, serving a structural purpose in neurological tissue. It is a major component of the gray matter in the cerebral cortex and constitutes up to 20% of the fatty acids in the retina. This structural role directly supports the development of the fetal central nervous system and visual acuity.
The demand for this nutrient significantly increases as pregnancy progresses, peaking during the third trimester when the fetal brain undergoes a rapid growth spurt. During this period, the developing fetus actively accumulates DHA, drawing heavily from the mother’s reserves via the placenta. Adequate maternal DHA intake during this stage supports neurogenesis and synaptogenesis, which are the formation of new neurons and the connections between them.
Current Recommended Daily Intake Guidelines
The question of how many milligrams of DHA are appropriate during pregnancy yields a range of responses from various global health organizations. However, a clear minimum recommendation exists: most consensus guidelines suggest pregnant women consume at least 200 milligrams (mg) of DHA per day. The World Health Organization (WHO) has historically recommended a daily intake between 100 mg and 200 mg of DHA.
The U.S. Food and Drug Administration (FDA) advises pregnant individuals to consume 8 to 12 ounces of low-mercury seafood per week, an intake level that typically provides approximately 200 mg of DHA per day. However, other expert groups, such as the International Society for the Study of Fatty Acids and Lipids (ISSFAL), recommend a slightly higher daily intake of 300 mg or more during pregnancy.
The American College of Obstetricians and Gynecologists (ACOG) advises that all pregnant women should aim for a total daily intake of at least 350 mg to 450 mg of DHA alone or combined with EPA. This higher figure reflects the understanding that many women have low baseline DHA levels and require more than the minimum for sufficient transfer to the fetus. For women at an increased risk of preterm birth, some studies suggest a considerably higher intake.
These recommendations can increase to between 600 mg and 1,000 mg of DHA per day to reduce the risk of early preterm delivery. This elevated dosage is often considered a targeted intervention for specific populations. Individual needs vary based on dietary habits and risk factors, meaning women with low fish consumption may require supplementation to achieve levels closer to 300 mg or more.
Primary Dietary Sources and Supplementation
The most direct way to meet DHA requirements is through the consumption of fatty, cold-water fish. Safe, low-mercury options like salmon, sardines, and mackerel are excellent natural sources of DHA and are recommended for consumption.
Concerns about mercury contamination are valid, which is why high-mercury species such as swordfish, king mackerel, and tilefish should be avoided during pregnancy. For individuals who do not regularly consume fish due to preference, dietary restrictions, or mercury concerns, supplementation is an effective alternative. Fish oil capsules are a common source, but they can vary widely in the amount of DHA they provide.
Another option is to use algae-based supplements, derived from the original source of DHA in the marine food chain. These plant-based supplements are an excellent choice for vegetarians and vegans and are inherently free of mercury contamination. DHA can also be found in fortified foods, such as certain eggs, milk, and yogurt products, offering additional dietary avenues for intake.
Safety, Timing, and Considerations
The optimal timing for beginning DHA intake starts even before conception to build up maternal stores, and should continue throughout the entire pregnancy. Consistent intake is particularly important, ideally starting no later than the second trimester, to support the rapid fetal brain development that occurs in the latter half of gestation. Continuing DHA supplementation while breastfeeding is also beneficial, as the nutrient is transferred through breast milk to support the infant’s ongoing neurological and visual development.
DHA is considered safe when taken at recommended levels, and there is no formally established Tolerable Upper Limit (TUL) for omega-3 fatty acids. Studies show that even dosages up to 1,000 mg of DHA per day are well-tolerated in pregnant individuals. While extremely high doses may occasionally cause mild side effects like gastrointestinal upset, these are not typically serious. Pregnant individuals should consult a healthcare provider to determine the most appropriate dosage based on their current diet and health status.