Omega-3 Fatty Acids and Maternal and Child Health: An Updated Systematic Review.

Abstract

To update a prior systematic review on the effects of omega-3 fatty acids (n-3 FA) on maternal and child health and to assess the evidence for their effects on, and associations with, additional outcomes. MEDLINE®, Embase®, the Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Centre for Agriculture and Biosciences (CAB) Abstracts from 2000 to August 2015; eligible studies from the original report; and relevant systematic reviews. We included randomized controlled trials (RCTs) of any defined dose of n-3 FA (or combination) compared to placebo, any other n-3 FA, or alternative dose with an outcome of interest conducted in pregnant or breastfeeding women or neonates (preterm or term). We also included prospective observational studies that analyzed the association between baseline n-3 FA intake or biomarker level and followup outcomes. Postnatal interventions began within a week of birth for term infants and within a week of beginning enteral or oral feeding for preterm infants. Standard methods were used for data abstraction and analysis, according to the Evidence-based Practice Center Methods Guide. We identified 4,275 potentially relevant titles from our searches, of which 95 RCTs and 48 observational studies met the inclusion criteria. Risk of bias was a concern with both RCTs and observational studies. Outcomes for which evidence was sufficient to draw a conclusion are summarized here with the Strength of Evidence (SoE). (Outcomes for which the evidence was insufficient to draw a conclusion are summarized in Appendix G of the report.). Most studies in this report examined the effects of fish oil (or other combinations of DHA and EPA) supplements on pregnant or breastfeeding women or the effects of infant formula fortified with DHA plus AA. As with the original report, with the exception of small increases in birth weight and length of gestation,n-3 FA supplementation or fortification has no consistent evidence of effects on peripartum maternal or infant health outcomes. No effects of n-3 FA were seen on gestational hypertension, peripartum depression, or postnatal growth. Apparent effects of n-3 FA supplementation were inconsistent across assessment methods and followup times for outcomes related to infant visual acuity, cognitive development and prevention of allergy and asthma. Future RCTs need to assess standardized preparations of n-3 and n-6 FA, using a select group of clinically important outcomes, on populations with baseline n-3 FA intakes typical of those of most western populations.