Neonatal Docosahexaenoic Acid in Preterm Infants associated with higher FSIQ scores at 5 years of age: Study
Children born preterm are more likely to have lower cognitive scores and have a higher risk of cognitive impairment than children born at full term, and the risk and severity of impairment increases as gestational age at birth decreases. Infants born at the earliest gestational ages are deprived of the placental supply of docosahexaenoic acid (DHA) that normally accumulates in the brain during the final trimester of pregnancy. DHA makes up approximately 30% of the lipid content of the brain and is integral to synaptosomal structure during neuronal development. Preterm infants born before 30 weeks' gestation have reduced DHA concentrations in neural tissues, which may contribute to poorer cognitive outcomes.
The current feeding practice for preterm infants is to provide approximately 20 mg of DHA per kilogram of body weight per day (the level naturally present in the milk of women consuming a Western diet), which is lower than the estimated in utero requirement of approximately 60 mg per kilogram per day.
In this study, we evaluated the general cognitive functioning of infants born before 29 weeks' gestation who had been part of a larger trial (involving 1273 infants) that evaluated the effect of providing the estimated requirement of DHA during the neonatal period as compared with standard practice for the prevention of bronchopulmonary dysplasia.17 We assessed general intelligence at 5 years of corrected age in a subgroup of these children.
Jacqueline F. Gould and team assessed general intelligence at 5 years in children who had been enrolled in a trial of neonatal DHA supplementation to prevent bronchopulmonary dysplasia. In the previous trial, infants born before 29 weeks' gestation had been randomly assigned in a 1:1 ratio to receive an enteral emulsion that provided 60 mg of DHA per kilogram of body weight per day or a control emulsion from the first 3 days of enteral feeds until 36 weeks of postmenstrual age or discharge home, whichever occurred first. Children from 5 of the 13 centers in the original trial were invited to undergo assessment with the Wechsler Preschool and Primary Scale of Intelligence (WPPSI) at 5 years of corrected age. The primary outcome was the full-scale intelligence quotient (FSIQ) score. Secondary outcomes included the components of WPPSI.
A total of 1273 infants underwent randomization in the original trial; of the 656 surviving children who had undergone randomization at the centers included in this follow-up study, 480 (73%) had an FSIQ score available — 241 in the DHA group and 239 in the control group. After imputation of missing data, the mean (±SD) FSIQ scores were 95.4±17.3 in the DHA group and 91.9±19.1 in the control group (adjusted difference, 3.45; 95% confidence interval, 0.38 to 6.53; P=0.03). The results for secondary outcomes generally did not support that obtained for the primary outcome. Adverse events were similar in the two groups.
Among children who had been born before 29 weeks' gestation, the mean FSIQ score at 5 years of corrected age was approximately 3.5 points higher among those who had received neonatal DHA supplementation than among those who had received a control emulsion. IQ scores obtained at approximately 5 years of age are considered to be relatively stable throughout the rest of childhood and early adulthood. The potential benefit to individual infants born before 29 weeks' gestation may extend beyond general cognition, because as IQ increases, the later risk of death decreases32 and quality of life increases.
In infants born before 29 weeks' gestation who had been enrolled in a trial to assess the effect of DHA supplementation on bronchopulmonary dysplasia, the use of an enteral DHA emulsion until 36 weeks of postmenstrual age was associated with modestly higher FSIQ scores at 5 years of age than control feeding.
Source: Jacqueline F. Gould, Ph.D., Maria Makrides, Ph.D., Robert A. Gibson; n engl j med 387;17
