OBJECTIVE: To evaluate the effects of normal vaginal delivery (NVD) on oxygen transport to the fetus. Study group and methods: Fifty newborn infants born by NVD and as a control group 50 infants born by elective Cesarean section (ECS) were studied. Factors reflecting oxygen transport to the fetus were measured in venous and arterial cord blood: pH, partial pressure of oxygen (pO2) and carbon dioxide (pCO2), oxygen saturation (SO2), blood oxygen content, base deficit, and lactic acid concentrations, erythropoietin concentrations, number of nucleated red blood cells and haemoglobin concentrations. RESULTS: There was no significant difference in venous blood oxygen content between the two groups of infants. However, arterial blood oxygen content was significanlty lower in the infants born by ECS than in those born by NVD (p