Omega-3 fatty acids are polyunsaturated fats, primarily docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), obtained through diet or supplementation. These nutrients are widely used by pregnant individuals to support fetal development. A common concern is whether to stop taking them as delivery approaches due to a long-held belief that they could potentially increase the risk of bleeding during childbirth. This article aims to provide clarity on the current medical understanding and recommendations regarding the continued use of standard omega-3 supplementation up until delivery.
The Essential Functions of Omega-3s in Fetal Development
Omega-3s, particularly DHA, serve as structural components for the developing fetal brain and retina. The accumulation of DHA in the fetal central nervous system accelerates significantly during the second half of pregnancy, with the highest rate occurring in the third trimester.
During this period, the fetus requires a daily accrual of approximately 50 to 70 milligrams of DHA. Adequate maternal intake is directly correlated with higher concentrations of DHA in the infant’s cord blood, which supports optimal neural function and visual acuity. Continuing to meet this need is important because the rapid development of the brain and eyes persists until birth and throughout the first two years of life.
Addressing the Concern: Omega-3s and Peripartum Bleeding Risk
The concern about stopping omega-3s is linked to the known biological mechanism by which these fatty acids influence blood clotting. Specifically, EPA competes with arachidonic acid for incorporation into platelet cell membranes. This competition can shift the body’s balance toward producing substances that have a mild antiplatelet effect, theoretically increasing the time it takes for blood to clot.
However, multiple large-scale studies have investigated the relationship between omega-3 intake and the risk of bleeding events. A systematic review and meta-analysis concluded that omega-3 polyunsaturated fatty acids are not associated with an increased risk of bleeding. This finding holds true for individuals on standard dosages, as any measurable effect on clotting time is not considered clinically significant.
A potential exception is the use of extremely high doses, such as those exceeding 3 grams of EPA and DHA combined per day. Even in these cases, the absolute increase in bleeding risk remains modest. One observational study noted an association between omega-3 supplementation and a higher adjusted odds of profuse postpartum hemorrhage. However, this study had limitations, including a retrospective design, meaning the findings do not establish a direct cause-and-effect relationship.
Current Medical Consensus on Continuing or Stopping Omega-3s
For individuals taking omega-3s at or near the standard recommended prenatal dosage, the current medical consensus supports continuing supplementation through delivery. Since the fetus continues to accumulate DHA rapidly until birth, stopping the supplement would interrupt this final stage of development. The benefit of supporting fetal neurodevelopment outweighs the minimal, non-clinically significant bleeding risk at standard doses.
The decision to stop omega-3s is usually reserved for specific, non-standard scenarios. If a person is taking a very high dose (over 3,000 mg of combined EPA and DHA daily) or has a pre-existing maternal clotting disorder, a healthcare provider might recommend cessation. In these rare situations, the provider may advise stopping the supplement approximately one to two weeks before a scheduled procedure, such as a planned Cesarean section.
For an expected vaginal delivery, stopping is less common because the timing is unpredictable and the benefits of continuous supplementation are valued. The ultimate decision should be made through a direct discussion with an obstetrician or midwife. They can evaluate the specific dosage, the balance of EPA and DHA, and any personal risk factors to provide tailored guidance.
Recommended Safe Daily Intake and Best Sources in Late Pregnancy
To ensure safe and effective supplementation, most expert guidelines recommend that pregnant individuals consume a minimum of 200 to 300 milligrams of DHA per day. This intake supports the ongoing high demand for DHA during the third trimester and beyond. When choosing a supplement, check the label for the specific DHA content, as the total amount of fish oil listed may not reflect the actual DHA amount.
Dietary sources of omega-3s are an excellent way to meet these requirements. Consuming two servings of low-mercury seafood per week can help cover a portion of the daily needs. Safe and effective sources of both DHA and EPA include:
- Salmon
- Sardines
- Trout
- Canned light tuna
Plant-based options, like algal oil, are also available and provide DHA directly. This is important because the body is inefficient at converting other plant-based omega-3s into DHA.