[The effects of halothane and enflurane on uterine activity during childbirth (author's transl)]

The effects of equipotent low concentrations of halothane and enflurane on uterine contractions during labour were studied by means of transcervical toko-ergometry. Administration of halothane was followed by a highly significant reduction of uterine activity to 48% +/- 14 of its original value. Ethrane in equipotent concentration of 1.0% reduced uterine activity in 5 women to only 83.7% +/- 29 (not significant). Five other women were also tested with ethrane in 1.5% concentrations: uterine activity was reduced to 79% +/- 24 of its original value (not significant). The findings indicate that low concentrations of ethrane relax uterine contractions less than do equipotent concentrations of halothane. The clinical applications of the observations are discussed.