8 DHA and preterm birth: what we’ve learned since the 2018 Cochrane Review

Abstract Abstract: Introduction A 2018 Cochrane Review concluded strong evidence that omega-3 fatty acids, including docosahexaenoic acid (DHA, 22:6n-3), prevented preterm birth (PB < 37wks gestation) by 11% and early PB (EPB<34wks gestation) by 42%, however, it did not determine dose or who was most likely to benefit from DHA supplementation. Objective The Assessment of DHA on Reducing Preterm Birth (ADORE) multicenter trial enrolled 1100 women between 12 and 20wks gestation and assigned them to 200 or 1000 mg/d DHA. Red blood cell phospholipid (RBC-PL) DHA and DHA intake (DHA-Food Frequency Questionnaire) were assessed at baseline. Results The higher dose reduced PB (PP = 0.95) and EPB (PP = 081). A secondary analysis found low DHA at baseline (<6%total fatty acids) or low DHA intake (<150mg/d) predicted who had reduced EPB (PP = 0.93) with 1000mg/d. Adherence to high dose (RBC-PL ≥8%) decreased PB by 58% (PP = 0.95) and EPB by 65% (PP = 0.94) in the low baseline DHA group. Black participants with high baseline DHA provided 1000mg had 6.4% PB and 2% EPB, below US rates. Our latest finding is that a FADS1 Insertion allele that increase arachidonic acid synthesis predicts women who benefit from high dose DHA supplementation; an allele found in 85.5% of Black and 48.6% of Other Races participating in ADORE. Conclusion Identification of the FADS I allele is a precision medicine strategy for primary prevention of PB and EPB. (Supported by NIH HD083292)