For infants with extremely low birthweight, extra parenteral amino acids for five days after birth do not increase survival free from neurodisability at two years, according to a study published in the Nov. 3 issue of the New England Journal of Medicine.

Frank H. Bloomfield, Ph.D., from the Liggins Institute in Auckland, New Zealand, and colleagues conducted a multicenter trial involving infants with <1,000 g. A total of 434 were randomly assigned to receive amino acids at a dose of 1 g/day (intervention group) or placebo in addition to usual nutrition for the first five days after (217 per group).

The researchers found that survival free from neurodisability was observed in 47.8 and 49.8 percent in the intervention and placebo groups, respectively (adjusted relative risk, 0.95; 95 percent confidence interval, 0.79 to 1.14; P = 0.56). Death before age 2 years occurred in 18.0 and 19.4 percent of the intervention and placebo groups, respectively (adjusted relative risk, 0.93; 95 percent confidence interval, 0.63 to 1.36); neurodisability occurred in 40.9 and 37.4 percent, respectively (adjusted relative risk, 1.16; 95 percent confidence interval, 0.90 to 1.50). Neurodisability was moderate-to-severe in 16.6 and 8.6 percent of children in the intervention and placebo groups, respectively (adjusted relative risk, 1.95; 95 percent confidence interval, 1.09 to 3.48).

"Amino acid intake in the placebo group fell within the range of the most recent recommendations of 2.5 to 3.5 g per kilogram per day," the authors write. "Our findings support these recommendations and suggest that intake levels higher than this are not needed to support growth and may have adverse effects on neurodevelopment."

More information: Frank H. Bloomfield et al, Early Amino Acids in Extremely Preterm Infants and Neurodisability at 2 Years, New England Journal of Medicine (2022). DOI: 10.1056/NEJMoa2204886

Camilia R. Martin, Parenteral Protein in Extremely Preterm Infants—More Is Not Better, New England Journal of Medicine (2022). DOI: 10.1056/NEJMe2212522

Journal information: New England Journal of Medicine