Melatonin Levels in Preterm and Term Infants and Their Mothers

Abstract

The prevention of perinatal brain damage following preterm birth remains a public health priority. Melatonin has been shown to be a promising neuroprotectant in neonatal preclinical models of brain damage, but few studies have investigated melatonin secretion in newborns. We hypothesized that melatonin circulating levels would be lower in preterm compared to term infants. We conducted a prospective, longitudinal, multicenter study to assess melatonin, and 6-sulfatoxy-melatonin (aMT6s) concentrations, measured by radioimmunoassay. Among 209 neonates recruited, 110 were born before 34 gestational weeks (GW) and 99 born after 34 GW. Plasma melatonin concentrations, measured at birth and on Day 3 were below detectable levels (≤7 pg/mL) in 78% and 81%, respectively, of infants born before 34 GW compared to 57% and 34%, respectively, of infants born after 34 GW. The distribution of plasma melatonin concentrations was found to be correlated with gestational age at both time-points (p < 0.001). Median urine aMT6s concentrations were significantly lower in infants born before 34 GW, both on Day 1 (230 ng/L vs. 533 ng/L, p < 0.0001) and on Day 3 (197 ng/L vs. 359 ng/L, p < 0.0001). In conclusion, melatonin secretion appears very low in preterm infants, providing the rationale for testing supplemental melatonin as a neuroprotectant in clinical trials.

Melatonin from an Antioxidant to a Classic Hormone or a Tissue Factor: Experimental and Clinical Aspects 2019

“…An interesting collaborative study from several clinical and academic French institutions provides here evidence that the melatonin circulating levels at day of birth are much lower-below detection-in 78% of infants born before 34 GW [18]. This was also confirmed with urine aMT6s concentrations.…”

Use of Melatonin in Oxidative Stress Related Neonatal Diseases

“…Three-to-five months may pass after birth before a full-term newborn produces melatonin, experiencing a transient deficiency in melatonin levels [ 39 ]. Preterm infant research has given unclear findings: reduced urine aMT6s levels have been described at birth [ 40 ], but other studies have reported decreased 6-sulfatoxy-melatonin urine concentrations for 13 weeks after birth in preterm infants when compared to term infants [ 41 ].…”

Melatonin Content of Human Milk: The Effect of Mode of Delivery

“…Some stressful conditions not ruled out in other studies may modify the results. 20 Indeed, the characteristics of the population studied in this research are more homogeneous, and fewer adverse inflammatory or oxidative effects were expected.…”