[Studies on cortisol levels in the maternal vein, umbilical artery, and umbilical vein in cases of fetal distress and neonatal asphyxia].

We measured maternal venous (MV), umbilical arterial (UA) and umbilical venous (UV) cortisol levels of 180 pregnancies at term, and investigated especially cases of fetal distress and neonatal asphyxia. No fetal distress and no neonatal asphyxia cases followed spontaneous vaginal deliveries (94), cesarean sections (18) or breech extractions (6). In cesarean section delivery, the cortisol levels of three individual samples were lower than in other modes of deliveries. The cortisol level of the umbilical artery was significantly higher than that of the umbilical vein in spontaneous vaginal delivery and cesarean section delivery. When spontaneous vaginal deliveries were classified into the fetal distress group and no fetal distress group, the cortisol levels of the umbilical artery and umbilical vein in the former group were significantly higher than those in the latter group. Furthermore, regardless of fetal distress there were significant positive correlations between the cortisol levels of MV & UA, MV & UV, and UA & UV. In addition, as the cortisol level of the maternal vein increased, the umbilical arterial-venous cortisol ratio (UA/UV) gradually approached 1.0. These data suggest that in fetal distress or neonatal asphyxia, the fetus may produce cortisol for itself independent of the mother.