Plasma-free carnitine levels in preterm infants with respiratory distress syndrome

ABSTRACT

Antenatal carnitine administration has been shown to induce fetal lung maturity by increasing pulmonary surfactant in animal and human studies. In this study, the aim was to investigate the status of carnitine in maternal and neonatal plasma of preterm infants with respiratory distress syndrome [RDS] in the first hours of life. We also aimed to characterize the carnitine status in these neonates with respect to sex, gestational age, birth weight, mode of delivery, and antenatal corticosteroid administration. Maternal plasma-free carnitine levels were determined before delivery and neonatal plasma-free carnitine levels were determined within 2 h of birth in preterm infants gestational age] who developed RDS in the first 6 h of life and in the control group. The results showed that the mean neonatal plasma-free carnitine level was significantly lower in preterm infants with RDS than in the control group [19.96 +/- 5.77 micro mol/L, and 37.9 +/- 5.77 micro mol/L, respectively; p = 0.001] while the mean maternal plasma-free carnitine levels were similar in both groups [33.28 +/- 9.58 micro mol/L, and 37.3 +/- 9.55 micro mol/L, respectively; p = 0.168]. Neonatal plasma-free carnitine levels correlated negatively with gestational age and birth weight in the RDS group [r = -0.512; p = 0.009 and r = -0.476; p = 0.016], and in the control group [r = -0.869; p = 0.0001 and r = -0.810; p-0.0001]. Sex, mode of delivery, and antenatal corticosteroid administration had no statistically significant effect on the level of plasma-free carnitine in the studied preterm infants. Low neonatal plasma-free carnitine levels in preterm infants with RDS maybe due to decreased maternal-fetal transfer of carnitine or to increased consumption of carnitine in fetal lung tissue for surfactant synthesis. This could be contributing factor in the pathogenesis of RDS in preterm infants