Most health organizations recommend pregnant women get at least 250 mg of combined DHA and EPA daily, plus an additional 100 to 200 mg of DHA on top of that. If you’re at higher risk for preterm birth or have a low omega-3 intake, the evidence supports a higher range of 600 to 1,000 mg per day. Here’s what the research says about getting the right amount.
The Baseline Recommendation
The standard guidance for women of childbearing age is a minimum of 250 mg per day of DHA and EPA combined, from food or supplements. During pregnancy, an additional 100 to 200 mg of DHA specifically is recommended, bringing the practical minimum to roughly 350 to 450 mg per day. This baseline supports normal fetal development and is the floor, not the ceiling.
For women with low omega-3 intake (which includes most women eating a typical Western diet low in fatty fish), clinical trials have shown significant benefits at higher doses. Supplementation in the range of 600 to 1,000 mg per day of DHA and EPA combined, or DHA alone, has been linked to meaningful reductions in preterm birth risk. A large Cochrane review covering 70 trials and nearly 20,000 women found that increased omega-3 intake was associated with a 42% reduction in early preterm birth (before 34 weeks) and an 11% reduction in late preterm birth.
Why DHA Matters More Than EPA for Your Baby
DHA is the omega-3 that your baby’s developing brain and eyes need most. It’s a structural building block of neural membranes and plays roles in the formation of new brain cells, nerve signaling, and protecting developing tissue from oxidative damage. The most rapid brain and retinal development happens in the second half of pregnancy, especially the third trimester, which is when fetal demand for DHA is highest.
Your body transfers DHA across the placenta preferentially, which means your own levels can drop significantly during pregnancy if you’re not replenishing them. This is why most recommendations specifically call out DHA rather than EPA as the priority nutrient for fetal development.
EPA’s Role in Maternal Health
EPA plays a different but complementary role. It supports your cardiovascular system and has the stronger evidence base for mood regulation. A meta-analysis in Translational Psychiatry found that omega-3 formulas with a higher EPA-to-DHA ratio (1.5:1 or greater) showed significant benefits for mild to moderate depression during pregnancy and postpartum, with few side effects.
If mood support is a priority alongside fetal development, look for a supplement that provides substantial amounts of both rather than DHA alone. Many prenatal omega-3 supplements are DHA-heavy, which is fine for the baby but may not be optimal if you also want the mood-related benefits of EPA.
When To Start Supplementing
The strongest fetal demand kicks in during the third trimester, but that doesn’t mean you should wait. Omega-3 recommendations apply from the onset of pregnancy, and there are likely benefits to starting even before conception. Building up your DHA stores early means your body has a ready supply when fetal brain growth accelerates. If you’re planning a pregnancy, starting supplementation during the preconception period is a reasonable approach.
Upper Limits and Safety
Omega-3 supplements are well tolerated during pregnancy at the doses typically recommended. Clinical trials have used up to 2,700 mg (2.7 g) per day of combined EPA and DHA in pregnant women without safety concerns. The European Food Safety Authority has not raised safety issues with daily intakes up to 5,000 mg of combined EPA and DHA in the general population.
The main theoretical concern at very high doses is a slight increase in bleeding tendency. The large Cochrane review on pregnancy supplementation did not find increased bleeding risk, but two cardiovascular trials using high-dose EPA in non-pregnant populations did observe a very small increase (0.1% more bleeding episodes per year). As a practical guideline, staying at or below 2,700 mg per day of combined EPA and DHA keeps you well within the safe range.
Putting the Numbers Together
Here’s a practical summary of where the targets fall:
- General minimum: 250 mg combined EPA and DHA, plus 100 to 200 mg extra DHA, totaling roughly 350 to 450 mg per day
- Optimal range for preterm birth prevention: 600 to 1,000 mg per day of DHA and EPA combined
- For mood support: Choose a formula where the EPA-to-DHA ratio is at least 1.5:1
- Upper safety threshold: Up to 2,700 mg per day has been used safely in pregnancy trials
Food Sources vs. Supplements
Two servings of fatty fish per week (salmon, sardines, anchovies, herring) can provide roughly 250 to 500 mg of EPA and DHA per day on average, depending on the fish and portion size. If you eat fish regularly, you may already be near the baseline. If you rarely eat seafood or follow a plant-based diet, supplementation is the most reliable way to reach adequate levels.
Algal oil supplements, derived from the microalgae that fish themselves eat, provide DHA directly and are the main plant-based option. Most algal oil products are DHA-dominant with little EPA, so if you want both, check the label or consider combining an algal DHA supplement with a separate EPA source. Fish oil and krill oil supplements typically provide both EPA and DHA in varying ratios, and labels list each amount separately so you can add them up.