New research proposes target omega-3 DHA level for pregnant women

A new scientific paper has, for the first time, proposed an omega-3 DHA target blood level of 5% or higher for pregnant women who want to reduce their risk of preterm birth. Published in the December edition of Nutrients, authors Kristina Harris Jackson, PhD, RD, and William S. Harris, PhD, discuss the ramifications of low DHA levels among pregnant women and why they need to strive for a DHA level of 5% or above.

DHA levels in pregnant women of 4.3% have been described in previous research as "very low," with 3.5% defined as being "exceedingly deficient." These levels, researchers believe, represent consistent inadequate intake, even though there are strong recommendations for DHA during pregnancy.

According to Drs. Jackson and Harris, ~70% of women of childbearing age in the US are likely below the DHA cut-point of 5%, and dietary intake data suggest that this group, including pregnant women, consumes just ~60 mg of DHA per day. Most experts recommend a minimum of 200 mg of DHA from fatty fish like salmon or an omega-3 supplement that contains DHA. Although some experts believe the dose should be higher in light of new research.

"Since the recommendations for women to consume fish and to take a 200 mg DHA supplement during pregnancy are not being heeded generally, there is a need to motivate practitioners and pregnant women to attend to these recommendations," the researchers said. "Having an objective prenatal blood DHA test could provide such motivation."

DHA has been the subject of several recent studies specifically connecting it with a reduced risk of preterm (before 37 weeks) and early preterm birth (before 34 weeks). In fact, a study published last November came to the conclusion that DHA could lower the risk of preterm and early preterm birth by 11% and 42%, respectively.

Another study published last August showed that women who had higher omega-3 levels were at significantly reduced risk of early preterm birth. "Early preterm birth has immense health, economic, and emotional costs. Our findings are consistent with the results of most randomized trials of long chain omega-3 fatty acid supplements in pregnancy and support the importance of ensuring adequate intake of these nutrients during pregnancy, either through fish intake or supplements, to help prevent early preterm birth," said co-author Andrew Thorne-Lyman, an associate research scientist at Johns Hopkins Bloomberg School of Public Health who worked on this study while a faculty member at Harvard's TH Chan School of Public Health.