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Taking a Larger Dose of DHA Supplements May Reduce Premature Birth Risks

DHA supplements.

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Key Takeaways

  • A new study suggests that pregnant people who take 1,000 mg of DHA supplements daily are at reduced risk of giving birth to their baby prematurely.
  • Docosahexaenoic acid, or DHA, is a specific omega-3 fatty acid that humans need to obtain from food or supplements.
  • Taking DHA supplements can be particularly helpful for pregnant people who have low levels of the nutrient.

A new study shows that pregnant women who are low in DHA may reduce their risk of early preterm birth when they supplement with 1,000 milligrams (mg) of DHA omega-3 fatty acid per day. This is well above the recommended 200 mg dose. 

“Many pregnancies would benefit from more supplemental DHA than in most prenatal supplements,” study author Susan E. Carlson, PhD, professor of nutrition in the department of dietetics and nutrition at the University of Kansas Medical Center, tells Verywell. “It is important that we educate women who are, or who are planning to become, pregnant to talk with their caregivers about DHA intake.”

What Is DHA?

Omega-3 fatty acids are known as “healthy fats” and play important roles in human health. Docosahexaenoic acid, or DHA, is a specific omega-3 fatty acid that humans need to obtain from food or supplements, as they cannot make this key nutrient in adequate amounts.

DHA plays a significant role in overall health. Specific to pregnancy, this fatty acid can help support a fetus’s brain and eye development in the uterus.

The best sources of DHA omega-3 fatty acids are:

  • Seafood
  • Krill oil
  • Fish oil supplements
  • Algae-based supplements

People can also get some DHA from foods fortified with the nutrient, like certain milks. Pregnant people are typically advised to take 200 mg of DHA every day to ensure adequate intake of this key fatty acid. 

While foods like walnuts, flax seeds, and chia seeds do contain omega-3 fatty acids, they do not contain DHA. Rather, they contain ALA, a fatty acid that does not offer the same benefit to the fetus. 

DHA levels are not routinely evaluated. However, since 80% of Americans don’t eat recommended amounts of seafood, it is safe to say that many people likely do not have adequate levels of the nutrient.

DHA Helps Reduce Early Preterm Birth Risk

Early preterm birth means that a baby is born before their due date—specifically, before 34 weeks of pregnancy. Not only can this result in a smaller baby, but it puts the baby at risk of experiencing challenges with their eyes, lungs, brain, and other organs.

While there are many factors that can contribute to giving birth early, research shows omega-3 fatty acids reduce the risk of preterm birth. But the exact dose needed to produce a positive effect is not confirmed. 

To help make more specific recommendations, researchers decided to evaluate whether a 1,000 mg dose of DHA would help. Eleven hundred pregnant people were either given 1,000 mg of supplemental DHA or 200 mg of the same fatty acid. 

Researchers found that, especially if the person had low DHA levels at the start of the trial, the higher dose of DHA supplementation resulted in fewer early preterm births versus those who only took 200 mg. These results were published in the journal EClinicalMedicine in May.

They also found that:

  • Pregnant people with low DHA status at the beginning of the trial who received a 1,000 mg supplement of DHA experienced half the rate of early preterm birth (2% of births) compared to those who received 200 mg of DHA (4%).
  • Of the pregnant people who had a high DHA status at the beginning of the trial, the rate of early preterm birth was 1.3%. This group didn't experience greater benefits when given a supplement of 1,000 mg per day. 

Ryan Kipping, RDN, CLEC, a prenatal registered dietitian and owner of The Prenatal Nutritionist, shares that DHA was “beneficial for not only lowering the risk of preterm birth, but also other adverse outcomes, like a visit to the NICU or feeding issues after birth.”

“We know that molecules that resolve inflammation are formed from DHA,” Carlson adds. “Although the mechanisms that lead to preterm birth are not known, one attractive hypothesis is that these molecules may be involved in preventing some preterm births.”

What This Means For You

If you are pregnant, ask your healthcare provider about your DHA levels. If they're low, supplementing with the fatty acid every day may help reduce your risk of premature birth.

What Can You Do Beyond Supplementing With DHA?

There are some causes for premature birth that are completely out of a person’s control, like being a certain age or having a family history of premature birth. But there are some steps you can take to reduce your risk.

During your pregnancy you can:

  • Avoid recreational drugs
  • Maintain a healthy weight
  • Manage stress

And as this May study emphasizes, including a daily DHA supplement at a dose of 1,000 mg per day may help you reduce your risk as well, especially if you are deficient in this key nutrient. 

Kipping cautions that there are a few risks when supplementing with DHA, like low blood pressure, too much Vitamin A (retinol), acid reflux, insomnia, and risk of bleeding. If you do decide to include this amount of DHA in your supplemental routine, you should consult with your healthcare provider first. 

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Article Sources
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  1. Carlson SE, Gajewski BJ, Valentine CJ, et al. Higher dose docosahexaenoic acid supplementation during pregnancy and early preterm birth: a randomised, double-blind, adaptive-design superiority trial. EClinicalMedicine. Published online May 17, 2021. doi:10.1016/j.eclinm.2021.100905

  2. Swanson D, Block R, Mousa SA. Omega-3 fatty acids EPA and DHA: health benefits throughout life. Adv Nutr. 2012 Jan;3(1):1-7. doi:10.3945/an.111.000893

  3. U.S. Department of Agriculture. Dietary guidelines for Americans, 2020-2025. Published December 2020.

  4. March of Dimes. Long-term health effects of premature birth. Updated October 2019.

  5. Middleton P, Gomersall JC, Gould JF, Shepherd E, Olsen SF, Makrides M. Omega-3 fatty acid addition during pregnancy. Cochrane Database Syst Rev. 2018 Nov 15;11(11):CD003402. doi:10.1002/14651858.CD003402.pub3