Aim: To investigate the serum thiol/disulphide homeostasis in deliveries complicated by nuchal cord (NC) and to compare the results with healthy deliveries (without NC). Methods: This prospective controlled study included 48 pregnant women complicated by NC and 48 similar gestational aged healthy pregnant women during labor. Fetal umbilical cord serum samples were collected during labor and the thiol/disulphide homeostasis was measured by using an automated assay method. The patients were followed up until end of the delivery and perinatal outcomes were recorded. Results: Fetal umbilical cord native thiol, total thiol, and disulphide levels as well as disulphide/native thiol and disulphide/total thiol ratios are impaired in labor with the presence of NC. There were no statistically significant differences in terms of maternal and gestational age at delivery and maternal number of gravida and parity, fetal gender, fifth Apgar scores <7, mode of delivery and fetal birth weight between groups. The group of patients with NC had higher emergency C/S numbers indicated for fetal distress and lower first Apgar scores Conclusions: Maternal serum thiol/disulphide homeostasis reflect transient effects of NC during labor regardless of labor type. Vaginal delivery can be safely and successfully performed in pregnancies complicated with NC.