Objective: Long-chain polyunsaturated fatty acids such as docosahexaenoic acid (DHA) influence immune function and inflammation; however, the influence of maternal DHA supplementation on infant morbidity is unknown. We investigated the effects of prenatal DHA supplementation on infant morbidity.
Methods: In a double-blind randomized controlled trial conducted in Mexico, pregnant women received daily supplementation with 400 mg of DHA or placebo from 18 to 22 weeks' gestation through parturition. In infants aged 1, 3, and 6 months, caregivers reported the occurrence of common illness symptoms in the preceding 15 days.
Results: Data were available at 1, 3, and 6 months for 849, 834, and 834 infants, respectively. The occurrence of specific illness symptoms did not differ between groups; however, the occurrence of a combined measure of cold symptoms was lower in the DHA group at 1 month (OR: 0.76; 95% CI: 0.58-1.00). At 1 month, the DHA group experienced 26%, 15%, and 30% shorter duration of cough, phlegm, and wheezing, respectively, but 22% longer duration of rash (all P ≤ .01). At 3 months, infants in the DHA group spent 14% less time ill (P < .0001). At 6 months, infants in the DHA group experienced 20%, 13%, 54%, 23%, and 25% shorter duration of fever, nasal secretion, difficulty breathing, rash, and "other illness," respectively, but 74% longer duration of vomiting (all P < .05).
Conclusions: DHA supplementation during pregnancy decreased the occurrence of colds in children at 1 month and influenced illness symptom duration at 1, 3, and 6 months.
Trial registration: ClinicalTrials.gov NCT00646360.