PURPOSE OF THE STUDY.
To assess whether prenatal supplementation with ω-3 (n-3) long-chain polyunsaturated fatty acids (LCPUFA) exerts a protective effect on the development of immunoglobulin E–mediated allergic conditions at 6 years of age in a prospective birth cohort.
A total of 706 children with a family history of allergic disease were enrolled into this study as part of the Docosahexaenoic Acid to Optimize Mother Infant Outcome trial.
Women with a singleton pregnancy (<21 weeks’ gestation) were recruited from the Docosahexaenoic Acid to Optimize Mother Infant Outcome randomized controlled trial (RCT) during an antenatal clinic visit. Participants were randomly assigned in a double-blind manner to receive either 500 mg of fish oil concentrate (∼800 mg/day docosahexaenoic acid and 100 mg/day eicosapentaenoic acid) or 500 mg of vegetable oil from 21 weeks’ gestation until delivery. Women were eligible to enroll in the follow-up study if their unborn children had a family history of atopic disease. Eligible offspring were evaluated in person at age 6 years for allergic disease via a validated questionnaire (International Study of Asthma and Allergies in Childhood), which assessed symptoms experienced over the previous 12 months and included skin prick testing for common food and environmental aeroallergens.
A total of 668 participants from the initial cohort were eligible for the follow-up study. Participant demographics were similar between the 2 groups. Seventy percent of participants had a history of maternal allergic disease compared with 54% who had a history of paternal allergic disease; 24% had a history of atopic disease in both parents. There were no significant differences in the reporting of allergic disease (eczema, wheeze, or rhinitis) on a symptom-based questionnaire between the n-3 LCPUFA and control groups. Rhinitis was the most common symptom (31.5%) affecting the birth cohort. There was also no difference between the groups in percent sensitized to at least 1 allergen on skin prick testing. The only minor difference was a reduction in the percentage sensitized to 1 of the common house dust mite allergens, Dermatophagoides farinae (13.4% vs 20.3%; adjusted relative risk, 0.67; 95% confidence interval, 0.44–1.00; P = .0495), in the intervention group.
Prenatal supplementation with n-3 LCPUFA did not reduce the development of allergic disease or sensitization in participants with a family history of atopy compared with control participants at the 6-year follow-up evaluation.
The quest to find a prenatal intervention that effectively prevents the development of allergic conditions in children continues. To date, this study is the largest RCT in which the researchers assessed the prenatal effect of fish oil supplementation. One of the strengths of the study includes its large sample size and high retention rate. However, no significant differences in primary clinical outcomes of eczema, wheeze, or rhinitis were detected, which is in contrast to previous RCTs, which vary in methodology and age at follow-up. Challenges from similar prenatal interventional studies arise from determining the type of intervention (n-3 fatty acids, vitamin D, probiotics, and prebiotics), the timing and duration of intervention, and what type of product and dosing to use. Although prenatal interventions such as these generally offer little risk to mother or infant, further studies are warranted to determine efficacy in preventing sensitization and progression to clinical disease.
- Copyright © 2017 by the American Academy of Pediatrics