Preterm infants produce less melatonin than term infants at 9 and 12 months of age: A randomized controlled trial

Abstract

Melatonin production is known to be delayed in preterm infants up to 6 months of age. We aimed to test the profile of melatonin production in these infants at 9–12 months of age. Twenty-three term and 23 preterm infants (gestational age: 29–34 weeks) were randomly assigned. We tested nocturnal urinary melatonin excretion, within a repeated measures design, both at 9 and 12 months of age. Nocturnal urine was extracted from diapers and urinary melatonin derivate (6-sulphatoxymelatonin) excretion was analyzed by enzyme-linked immunosorbent assay assays. Preterm infants had significantly lower urinary melatonin excretion both at 9 and 12 months of age as compared to term infants. At 9 months: 8502 ± 6215 vs. 12,735 ± 10,284 ng, and at 12 months: 8623 ± 5095 vs. 14,985 ± 10,890 ng respectively, (F [1,42]=4.276), (P < 0.05). At 9 and 12 months of age, the delayed maturation of melatonin production is still persistent in preterm infants as compared to term mates. The impact of persistent decreased melatonin production in preterm infants up to 12 months of age on their psychomotor and lung development is to be elucidated.

Keywords

6-sulphatoxymelatonin - developmental delay - melatonin treatment - oxygenation - preterm infants