Effects of different arachidonic acid supplementation on psychomotor development in very preterm infants; a randomized controlled trial

Background & aims: Nutritional supplementation with polyunsaturated fatty acids is important in preterm infants neurodevelopment, but it is not known if the omega-6/omega-3 ratio affects this process. This study was designed to determine the effects of a balanced contribution of arachidonic acid in very preterm newborns fed with formula milk. Methods: This was a randomized trial, in which newborns <1500 g and/or <32 weeks gestational age were assigned to one of two groups, based on the milk formula they would receive during the first year of life. Initially, 60 newborns entered the study, but ultimately, group A was composed of 24 newborns, who were given formula milk with an omega-6/omega-3 ratio of 2/1, and Group B was composed of 21 newborns, given formula milk with an omega-6/omega-3 ratio of 1/1. The infants were followed up for two years: growth, visual-evoked potentials, brainstem auditory-evoked potentials, and plasma fatty acids were periodically measured, and psychomotor development was assessed using the Brunet Lezine scale at 24 months corrected age. A control group, for comparison of Brunet Lezine score, was made up of 25 newborns from the SEN1500 project, who were fed exclusively with breast milk. Results: At 12 months, arachidonic acid values were significantly higher in group A than in group B (6.95 +/- 1.55 % vs. 4.55 +/- 0.78 %), as were polyunsaturated fatty acids (41.02 +/- 2.09 % vs. 38.08 +/- 2.32 %) achieved a higher average. Group A achieved a higher average Brunet Lezine score at 24 months than group B (99.9 +/- 9 vs. 90.8 +/- 11, p = 0.028). The Brunet Lezine results from group A were compared with the control group results, with very similar scores registered between the two groups (99.9 +/- 9 vs. 100.5 +/- 7). There were no significant differences in growth or evoked potentials between the two formula groups. Conclusions: Very preterm infants who received formula with an omega-6/omega-3 ratio of 2/1 had higher blood levels of essential fatty acids during the first year of life, and better psychomotor development, compared with very preterm newborns who consumed formula with an omega-6/omega-3 of 1/1. Therefore, formula milk with an arachidonic acid quantity double that of docosahexaenoic acid should be considered for feeding very preterm infants.