Melatonin Levels in Preterm and Term Infants and Their Mothers

Area of Science:

• Neonatal research
• Neuroscience
• Endocrinology

Background:

• Perinatal brain damage prevention in preterm infants is a critical public health concern.
• Melatonin shows neuroprotective potential in preclinical models, but its secretion in newborns is understudied.

Purpose of the Study:

• To investigate melatonin and 6-sulfatoxy-melatonin (aMT6s) concentrations in preterm versus term infants.
• To test the hypothesis that preterm infants exhibit lower circulating melatonin levels.

Main Methods:

• Prospective, longitudinal, multicenter study involving 209 neonates.
• Radioimmunoassay measurement of plasma melatonin and urine aMT6s concentrations at birth and on Days 1 and 3.
• Comparison of melatonin and aMT6s levels based on gestational age (preterm <34 GW vs. term ≥34 GW).

Main Results:

• Plasma melatonin was below detectable levels in a higher percentage of preterm infants (78-81%) compared to term infants (34-57%) at birth and Day 3.
• Melatonin concentrations significantly correlated with gestational age at both time points (p < 0.001).
• Median urine aMT6s concentrations were significantly lower in preterm infants on Day 1 (230 ng/L vs. 533 ng/L) and Day 3 (197 ng/L vs. 359 ng/L).

Conclusions:

• Melatonin secretion is markedly reduced in preterm infants.
• The observed low melatonin levels in preterm neonates provide a scientific basis for clinical trials investigating melatonin as a neuroprotective agent.