Interleukin-1 receptor antagonist in cord blood: Effects of labor and fetal distress

Objective: To evaluate the effect of labor pains or fetal distress on concentrations of interleukin-1 receptor antagonist (IL-1ra) in cord blood. Methods: Umbilical cord interleukin-1 beta (IL-1 beta) and IL-1ra were measured in 24 normal appropriately grown newborns delivered vaginally (VD group), 10 normal appropriately grown newborns delivered by elective cesarean section (ECS group), and 5 appropriately grown newborns with fetal distress (FD group). Umbilical cord arterial blood pH and PO2 were also measured. Results: Umbilical arterial blood pH and PO2 in the VD group were not significantly different from those in the ECS group. Umbilical artery blood pH and PO2 in the FD group were significantly lower than those in the VD group (p < 0.05). Umbilical artery blood pH in the FD group was significantly lower than that in the ECS group (p < 0.05), but no significant difference for umbilical artery blood PO2 was found between the FD and ECS groups. IL-1 beta levels were undetectable in the three groups of neonates. There were no significant differences for concentrations of IL-1ra in cord blood among the groups. Conclusion: These results suggest that the labor pain or fetal distress does not affect concentrations of IL-1ra in cord blood.