Concentrations of
progesterone and
estradiol (E2) were measured in parturient serum and in fetal cord serum during normal labor and in women with functional
dystocia. In the study group, there were no cases of
cephalopelvic disproportion. In
oxytocin-resistant
dystocia, the course of labor could not be corrected with
oxytocin. To ascertain the effect of
oxytocin, we included a number of women whose labor had been induced with
oxytocin, followed by normal cervical dilatation and descent of the fetus. All the parturients were grouped retrospectively into those with normal labor and those with
dystocia, based on previous definitions. The serum concentrations of
progesterone in both the fetal cord and maternal vein were found to be significantly lower in the
oxytocin-resistant
dystocia group than in women in spontaneous normal labor and those with
oxytocin-
induced labor and normal progression (P less than .05-.005).
Oxytocin had no evident effect on the serum concentration of either
progesterone or E2, nor did concentrations vary following epidural blockade. Serum E2 concentrations in the maternal vein were similar in all delivery groups. Fetal cord E2 serum concentrations were similar in all vaginal deliveries. Women with the most severe
oxytocin-resistant
dystocia, delivered by cesarean, had significantly lower serum concentrations of E2 in fetal cord serum compared with the vaginally delivered women (P less than .001).