Keim SA, et al. - Researchers ascertained if 6 months of daily docosahexaenoic acid (DHA) supplementation improves developmental outcomes in a randomized clinical trial of 377 US children aged 1 year who were born preterm. In children born prematurely, 6 months’ daily DHA+arachidonic acid (AA) supplementation did not improve cognitive development or early measures of executive function vs placebo. They observed small- to medium-magnitude negative effects for language ability among children of lower birth weight and for effortful control for children from all but the very lowest income strata. For children who were born preterm, these findings did not support DHA supplementation in the second year of life.

Methods

• It was a randomized, fully masked, placebo-controlled trial.
• This trial was conducted from April 26, 2012 to March 24, 2017 at a large US pediatric academic center with 9 neonatal intensive care units.
• For this analysis, children born at less than 35 weeks’ gestation who were 10 to 16 months corrected age had 6 months of intervention.
• Out of 2,363 children evaluated, 982 were eligible, 605 declined, and 377 enrolled and were randomized.
• Analyses were according to intent to treat.
• Main interventions analyzed were one-to-one allocation to receive daily microencapsulated DHA, 200 mg, and AA, 200 mg (DHA+AA), or microencapsulated corn oil (placebo).
• The primary outcome specified a priori was Bayley Scales of Infant and Toddler Development, third edition (Bayley-III), cognitive composite score at 16 to 22 months corrected age.
• Bayley-III language and motor composite scores and Infant Behavior Questionnaire–Revised and Early Childhood Behavior Questionnaire effortful control and activity level scores were included secondary outcomes.
• By income, sex, and birth weight, subgroup analyses defined a priori.

Results

• According to the findings, among 377 children randomized and included in the analysis (182 girls and 195 boys; median corrected age, 15.7 months), 338 children (89.7%) had complete data on the primary outcome.
• Between the DHA+AA and placebo groups (difference in change, 0.5 [95% CI, –1.8 to 2.8]; effect size, 0.05; P=.66), Bayley-III cognitive scores did not vary.
• Findings revealed that assignment to the DHA+AA group had a small to medium negative effect on Bayley-III language scores among children with lower birth weights (eg, a child with a birth weight of 1,000 g assigned to receive DHA+AA experienced a 4.1-point relative decrease, while a child assigned to placebo did not; P=.03 for interaction).
• Similarly, supplementation had a negative impact on effortful control scores among children with annual household incomes greater than $35,000 (difference in change, –0.3 [95% CI, –0.4 to –0.1]; effect size, –0.37; P=.01).
• It was noted that Bayley-III motor scores and activity level scores were unaffected.