Plasma carnitine levels in preterm infants with respiratory distress syndrome

Background: 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. Methods: Maternal plasma carnitine levels were determined before delivery and neonatal plasma carnitine levels were determined within 2 h of birth in preterm infants (< 34 weeks gestational age) who developed RDS in the first 6 h of life and in the control group. Results: The mean neonatal plasma free carnitine level was significantly lower in preterm infants with RDS than in the control group (28.3 +/- 8.8 mumol/L and 36.9 +/- 18.4 mumol/L, respectively; P < 0.05) while the mean maternal plasma-free carnitine levels were similar in both groups. Conclusions: Low neonatal plasma carnitine levels in preterm infants with RDS may be due to decreased maternal-fetal transfer of carnitine or to increased consumption of carnitine in fetal lung tissue for surfactant synthesis. This could be a contributing factor in the pathogenesis of respiratory distress syndrome in preterm infants.