NUTRI-FACTS editors had the opportunity to speak with Susan Carlson, Ph.D., AJ Rice professor of nutrition and university distinguished professor at the University of Kansas Medical Center, to get her unique perspective about new omega-3 research focused on preterm birth, which was published recently in the Cochrane Review.
NUTRI-FACTS Editors: World Prematurity Day was recently recognized in November 2018. What is the prevalence of preterm birth and the health outcomes associated with prematurity? How has this changed over time?
Susan Carlson, Ph.D.: Nearly 10 percent of all infants born in the U.S. are preterm, meaning they are born before 37 weeks gestation. In 2017, the last year for which data are available from the CDC, reports showed a small increase in rate for the third consecutive year with the increase found in non-Hispanic black women and Hispanic women. A smaller percentage of births (approximately 3.8 percent) occur before 34 weeks gestation, however, these infants typically experience a much longer hospitalization and are at greater risk for morbidity and mortality than preterm infants born after 34 weeks. Preterm birth is associated with an increased risk for cognitive impairment and psychiatric disorders, including ADHD and depression, breathing problems, feeding difficulties, cerebral palsy and vision and hearing problems.
NF: Can nutritional interventions play a role in reducing the risk of prematurity? What does the latest scientific research indicate?
SC: A Cochrane review released in November 2018 shows strong evidence that preterm birth can be reduced by 11 percent and early preterm birth by 42 percent if women consume a supplement of long chain omega-3 fatty acids. Most studies that showed benefit provided at least 500 mg of the omega-3 fatty acid docosahexaenoic acid, also called DHA. One of the studies included in that review, the Kansas University DHA Outcomes Study (KUDOS) was conducted in the US. That trial, which randomized 350 women to placebo or 600 mg per day of DHA beginning in the second trimester of pregnancy found a highly significant reduction in birth before 34 weeks (0.6 vs 4.8 percent) and infants born less than 1,500 grams (0 vs 3.4 percent) in the DHA group compared to the placebo group.
NF: What should healthcare professionals be recommending to pregnant women based on this new evidence? Is this different to what has been recommended in the past?
SC: Guidance for health professionals from one author of the Cochrane Review suggests recommending pregnant women consume an omega-3 fatty acid supplement containing at least 500 mg of DHA beginning early in the second trimester of pregnancy. The authors point out that prenatal supplements typically contain less than 200 mg of omega-3 fatty acids. Prior to this review, information on which to make recommendations was limited to individual studies, not considered strong evidence.
NF: Could insufficient omega-3 supplementation be considered an issue and/or risk of having a baby before 37 weeks gestation?
SC: Yes, this may be inferred by the significant reduction in preterm birth in randomized trials of omega-3 fatty acid supplementation.
NF: Did you find there was a significant link between supplement intake and maternal age or education?
SC: We have done several randomized trials of DHA supplementation in pregnancy. We did report that age and education were related to compliance with capsule intake. Age and education appear to be linked to choice of a prenatal supplement containing DHA.
NF: What measures can be taken to raise awareness of the benefits omega-3 intake has for maternal and infant outcomes?
SC: Education of obstetricians, family practice physicians and nurse practitioners who care for pregnant women would be a start. A dietary reference intake (DRI) for omega-3 fatty acids would signify a recognized requirement for long chain omega-3 fatty acids.
To learn more about the recent Cochrane Review research and researcher omega-3 recommendations, please visit www.sahmriresearch.org.