Protocols › DHA (docosahexaenoic acid)

DHA in pregnancy

Goal: For pregnancy: the DHA doses that trials gave, and what they found for preterm birth and the child's development.

Each protocol describes what studies used, for one goal or for one group of people. It is not advice for you: talk to a doctor before you start a supplement.

Updated 9 Nov 2026
Dose

Trials gave 600 mg a day (KUDOS), 800 mg a day (DOMInO), and 1000 mg against 200 mg a day (ADORE).[1][2][3] EFSA advises 100 to 200 mg of DHA a day on top of the 250 mg of EPA and DHA advised for all adults.[4]

Form

Capsules: DHA-rich fish oil in DOMInO, algal DHA oil in ADORE.[2][3]

How long

From before week 20 or 21 of pregnancy until birth.[1][2]

What studies found

In a Cochrane review of 70 trials, omega-3 fats lowered birth before 34 weeks from 4.6% to 2.7%.[5] In ADORE, early preterm birth was 1.7% with 1000 mg and 2.4% with 200 mg, and 2.0% against 4.1% in women with low DHA at the start.[3] The largest trial, ORIP, found no difference: 2.2% against 2.0%.[6] A 2026 review of 19 trials found no benefit for the child's brain development.[7]

Ask a doctor first

Omega-3 fats in pregnancy probably made pregnancies longer than 42 weeks more common: 2.6% against 1.6%.[5] In ORIP, very large babies were more common with omega-3.[6] Cod liver oil also contains vitamins A and D, which can be harmful in excess.[8]

Women who are pregnant should ask a doctor or pharmacist before they start a supplement.[4]

References

  1. DHA supplementation and pregnancy outcomes. Carlson SE, Colombo J, Gajewski BJ, Gustafson KM, Mundy D, Yeast J, et al. Am J Clin Nutr, 2013. PMID 23426033
  2. Effect of DHA supplementation during pregnancy on maternal depression and neurodevelopment of young children: a randomized controlled trial. Makrides M, Gibson RA, McPhee AJ, Yelland L, Quinlivan J, Ryan P JAMA, 2010. PMID 20959577
  3. Higher dose docosahexaenoic acid supplementation during pregnancy and early preterm birth: A randomised, double-blind, adaptive-design superiority trial. Carlson SE, Gajewski BJ, Valentine CJ, Kerling EH, Weiner CP, Cackovic M, et al. EClinicalMedicine, 2021. PMID 34308309
  4. Omega-3 Fatty Acids: Fact Sheet for Health Professionals. NIH Office of Dietary Supplements. ods.od.nih.gov
  5. Omega-3 fatty acid addition during pregnancy. Middleton P, Gomersall JC, Gould JF, Shepherd E, Olsen SF, Makrides M Cochrane Database Syst Rev, 2018. PMID 30480773
  6. A Randomized Trial of Prenatal n-3 Fatty Acid Supplementation and Preterm Delivery. Makrides M, Best K, Yelland L, McPhee A, Zhou S, Quinlivan J, et al. N Engl J Med, 2019. PMID 31509674
  7. Impact of Omega-3 Fatty Acid Docosahexaenoic Acid Supplementation in Individuals During Pregnancy on Neurodevelopment and Growth of Offspring: Systematic Review and Meta-Analysis. Xie L, Zhou M, Lu L, Ning X, Song Y Dev Psychobiol, 2026. PMID 42494300
  8. Omega-3 Supplements: What You Need To Know. NIH National Center for Complementary and Integrative Health, 2024. www.nccih.nih.gov