[Studies on the cortisol levels in maternal vein, umbilical artery, and umbilical vein classified according to the mode of delivery].Nihon Sanka Fujinka Gakkai Zasshi. 1983 May; 35(5):612-20.NS
We measured maternal venous(MV), umbilical arterial(UA), and umbilical venous(UV) cortisol levels of 180 pregnancies at term. In vacuum extraction cases, the cortisol levels of three individual samples were significantly higher than in other modes of delivery. In cesarean section delivery the cortisol levels of three individual samples were the lowest of all modes of delivery. The cortisol level of MV was higher than that of UA and UV in all deliveries. The cortisol levels of three samples showed no difference between the induced labor group and the spontaneous onset of labor group regardless of the delivery mode. In spontaneous vaginal delivery the cortisol levels of three individual samples were significantly higher in primipara than in multipara. Positive correlation was observed in all modes of delivery between the cortisol levels of MV & UA, MV & UV, and UA & UV. There was a negative correlation between the cortisol levels of MV and umbilical arteriovenous cortisol difference in multipara spontaneous vaginal deliveries. There was also a negative correlation between cortisol levels of MV and the umbilical arterial/venous ratio. These data suggest that the fetus may produce cortisol by itself and maternal cortisol may inflow to the fetus.