The Relationship Between Fish Oil Supplementation During Pregnancy and Incidence of Asthma in Children

Background: The incidence of asthma is increasing in the United States. Some researchers believe this rise is due to higher levels of n-6 fatty acids in relation to n-3 fatty acids that are found in cold-water fish. Several studies over the years have tried to discern if increasing fish oil in the diet or by supplementation can decrease the incidence of asthma in children. However, the results of these studies are not in agreement. Methods: A comprehensive search of available medical literature was performed using MEDLINE-Ovid, CINAHL, and Web of Science using the keywords: fatty acids, omega-3s, fish oil, LCPUFAs, wheezing, asthma, respiratory sounds, pregnancy, and perinatal. Studies were assessed for quality based on GRADE criteria. Results: There were 264 articles that were screened, 5 of which applied to the clinical question with only 2 articles meeting the eligibility criteria. One study found a significant decrease in the incidence of asthma in children when mothers were supplemented with high dose fish oil during pregnancy. The other study found no significant difference in the incidence of asthma in children of mothers supplemented with fish oil during pregnancy when compared to the control group. Overall the quality of evidence is low and further research needs to be done to explore key findings. Conclusion: Using fish oil supplements during pregnancy to prevent asthma in children cannot be strongly recommended at this time. However, it is reasonable for mothers to choose to supplement fish oil during pregnancy since the harm is low and the benefit may be great if further research can support recent findings