Comparison of fetal heart rate patterns and acid-base balance between early and late rupture of the membranes.

Abstract

Subject and Method: The thirty-two patients are all multiparous at term without hnown complicatiohs, and induced electively with artificial rupture of the membranes and continuous Infusion of oxytocin and prostaglandin F^K . Early rupture group is consisted of 16 patients where labor was induced with artificial rupture of the membranes followed by the above combination of oxytocics, whereas in late rupture group of 16 patients with the combination of oxytocics followed by artificial membrane rupture after the cervical dilatation of more than 5cm. FHR was monitored using Corometrics FMS 111 from the Start of induction until delivery, directly with spiral electrode in all patients after the membrane rupture, except in late rupture group where indirect technic was used until the rupture. All cases had balanced analgesia and anesthesia. At the time of delivery, umbilical blood specimens were taken for gas and acid-base determinations. FHR patterns were compared in terms of baseline level, long term variability, acceleration, early, variable and late decelerations at three phases of labor, namely before 5cm, 5 to 7cm, and after 8cm of cervical dilatationf which were further devided into 20-minute segments for the evaluation of findings. When positive findings of FHR patterns were noted in more than 50% of the 20-minute segment, the segment was judged positive. Those positive segments were expressed in percentage among each phase.