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Increased Levels of DHA May Reduce Likelihood of Preterm Births

pregnant woman holding prenatal vitamins

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Key Takeaways

  • A study finds that higher dosages of DHA may lower the risk of early preterm birth.
  • Some prenatal vitamins may not provide enough DHA for pregnant women.
  • Certain foods are valuable sources of DHA, but an additional supplement may still be needed.

Supplements of docosahexaenoic acid (DHA), an omega-3 fatty acid, may help significantly decrease the risk of early preterm births, according to a study published in EClinicalMedicine, a clinical journal of The Lancet.

Although many pregnant women take a multivitamin that contains DHA, it may not be enough. Researchers with the University of Kansas and the University of Cincinnati noted that increasing DHA intake to a dose of 1,000 milligrams (mg) can help lower the risk of early preterm birth. From a healthier diet to taking a supplement, increasing a pregnant woman’s DHA levels can positively impact her baby.

Learning the Importance of DHA

Between 2016 and 2020, participants took part in the randomized, double-blind study. In what is referred to as a superiority trial, researchers compared 1,100 women to see if taking 1,000 mg of DHA was superior to taking 200 mg of the supplement, to lessen the risk of preterm birth.

Gwenneth Simmonds, PhD, CNM

DHA is an omega-3 fatty acid essential for brain development in pregnancy and early childhood. It also decreases the body’s inflammatory response which is where it can impact preterm birth.

— Gwenneth Simmonds, PhD, CNM

They found that women who took the higher dosage of DHA had a lower rate of early delivery. Researchers also discovered measures women should take if they initially have low DHA levels.

“Our study shows that women who start prenatal care with low DHA status, typically women not already taking a prenatal supplement with DHA or not eating significant amounts of seafood, need to consume about a gram of DHA for the remainder of the pregnancy to lower rates of early (less than 34 weeks) and late preterm birth (34 to 36.9 weeks),” explains Susan E. Carlson, PhD, AJ Rice Professor of Nutrition and University Distinguished Professor, first author of the study.

The study was dependent upon women taking their supplements, which was a weakness if the DHA was not taken consistently. However, there was sufficient data to draw conclusions about a pregnant woman’s need for an adequate supply.

Sources of DHA

In addition to DHA supplements that are available, there are also nutritional sources. Fatty fish, such as tuna, trout, mackerel, and salmon are good choices. Eggs also provide some DHA. Flaxseed, chia seeds, and walnuts are good sources of alpha-linolenic acid (ALA), an omega-3 fatty acid that is converted to DHA in the body.

Susan E. Carlson, PhD

The implication of the study is that women need to consume DHA during pregnancy to optimally reduce their risk of preterm birth; and the amount they should consume is higher than in most prenatal supplements.

— Susan E. Carlson, PhD

Dr. Carlson noted that study participants only consumed, on average, about 80 mg of dietary DHA per day, a number that is far too small to be properly effective.

Healthy development of a fetus relies on appropriate amounts of DHA.

“DHA is an omega-3 fatty acid essential for brain development in pregnancy and early childhood. It also decreases the body’s inflammatory response which is where it can impact preterm birth,” states Gwenneth Simmonds, PhD, CNM.

Women may rely on a prenatal vitamin to have all of what they need during pregnancy. That can be a cause for concern.

“The implication of the study is that women need to consume DHA during pregnancy to optimally reduce their risk of preterm birth, and the amount they should consume is higher than in most prenatal supplements,” Dr. Carlson advises. In fact, she noted, some prenatal supplements may
provide no DHA at all.

It’s important to carefully consider the best prenatal vitamin to take and consult with a physician to ensure appropriate levels of needed vitamins and minerals.

A Public Health Issue

The CDC notes that in 2019, one out of every 10 infants in the United States was a preterm birth earlier than 37 weeks of pregnancy. In addition to higher rates of infant mortality and disability, those children can also suffer from vision problems, breathing difficulties, developmental delays,
and cerebral palsy.

Along with the costs of treatment, caring for a child struggling with these issues can exact a weighty emotional and mental toll on the family.

The detrimental impact underscores the necessity of proper prenatal care, including vitamin and mineral intake.

“Preterm birth is a significant public health problem in this country, so finding ways to address and reduce it is critical,” states Dr. Simmonds.

Results Impacting Future Care

The best place to begin with a healthy pregnancy is providing women with the information they need to make beneficial choices.

“Educating women and their providers about this finding and ensuring that higher dose supplements are available and affordable could dramatically reduce early preterm (less than 34 weeks) and preterm birth (less than 37 weeks),” Dr. Carlson advises.

Taking a long-term approach to the health and well-being of future generations can start with implementing smarter solutions now.

What This Means For You

Prenatal care involves more than doctor visits and even taking prenatal vitamins. As shown by this study, prenatal care means taking the extra step of ensuring that you are receiving optimal levels of all of the supplements that you need. As an active participant in your healthcare, finding out that little extra bit of information, can go a long way in giving your body all that it needs for a healthy pregnancy.

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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. 2021;36. doi:10.1016/j.eclinm.2021.100905

  2. National Institutes of Health, Office of Dietary Supplements. Omega-3 fatty acids: fact sheet for health professionals. Updated March 26, 2021.