Prenatal Docosahexaenoic Acid Supplementation and Offspring Development at 18 Months: Randomized Controlled Trial

OBJECTIVE: We evaluated the effects of prenatal docosahexaenoic acid (DHA) supplementation on offspring development at 18 months of age. DESIGN: Randomized placebo double-blind controlled trial. SETTINGS: Cuernavaca, Mexico. PARTICIPANTS AND METHODS: We followed up offspring (n = 730; 75% of the birth cohort) of women in Mexico who participated in a trial of DHA supplementation during the latter half of pregnancy. We assessed the effect of the intervention on child development and the potential modifying effects of gravidity, gender, SES, and quality of the home environment. INTERVENTIONS OR MAIN EXPOSURES: 400 mg/day of algal DHA. OUTCOME MEASURES: Child development at 18 months of age measured using the Spanish version of the Bayley Scales of Infant Development-II. We calculated standardized psychomotor and mental development indices, and behavior rating scale scores. RESULTS: Intent-to-treat differences (DHA-control) were: Psychomotor Developmental Index -0.90 (95% CI: -2.35, 0.56), Mental Developmental Index -0.26 (95% CI: -1.63, 1.10) and Behavior Rating Scale -0.01 (95% CI: -0.95, 0.94). Prenatal DHA intake attenuated the positive association between home environment and psychomotor development index observed in the control group (p for interaction = 0.03) suggesting potential benefits for children living in home environments characterized by reduced caregiver interactions and opportunities for early childhood stimulation. CONCLUSIONS: Prenatal DHA supplementation in a population with low intakes of DHA had no effects on offspring development at 18 months of age although there may be some benefit for infants from poor quality home environments. TRIAL REGISTRATION: Clinicaltrials.gov NCT00646360