Differences of Fetal Heart Rate Patterns between Cephalic and Breech Presentation in Induced Labor

Abstract

More obstetricians are reluctant to induce labors of breech presentation. We have been managing both cephalic and breech labors by elective induction. In this study evaluated were fetal heart rate patterns in the first stage Of breech labor in comparison with those of cephalic labor.Subject and Method; Randomly selected patients were monitored electronically. Fourty-eight monitor records (28 primiparas and 20 multiparas) in breech group and twenty-six records (10 primiparas and 16 multiparas) in cephalic group were used for comparison. Labors were either induced or augmented in all cases by continuous intravenous infusion of oxytocics with or without artificial rupture of the membranes. Analgesia and anesthesia were given to all patients in the form of balanced analgesia and anesthesia, modified neuroleptanalgesia (diazepam and pentazocine), or epidural anesthesia. FHR was monitored by Corometrics FMS 111, always by direct technic after membrane rupture and by indirect technic before it. Among FHR patterns evaluated were baseline FHR level f baseline long term variability, acceleration, early, variable and late decelerations at the cervical dilatation of less than 5cm, 5 to 7cm, and more than 8cm, respectively. Those three phases of labor 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. The positive segments were expressed in percentage in each phase.Result; Among variables of the two groups of patients, cevical dilatation and effacement at the time of membrane rupture were significantly more advanced in multiparous breech than in multiparous cephalic group. Otherwise these and Station of the presenting part were not statistically different between groups. Significant changes were noted in primiparous breeches with progress of labor in terms of long term variability, early and variable decelerations. Multiparous breeches showed significant changes with labor progression in terms of long term variability, acceleration, and variable deceleration. Among primiparous breeches, significantly lower incidence was noted than among cephalics in terms of long term variability at the cervical dilatation of more than 5cm, acceleration at less than 5cm, and early deceleration at 5 to 7cm. Compared with multiparous cephalics, multiparous breeches showed significantly higher incidence of tachycardia before cervical dilatation of 5cm, and of long term variability at 5 to 7cm, while significantly lower incidence of acceleration before 5cm, and early deceleration after 5cm.Comment; Such ominous FHR patterns äs variable and late decele-0300-5577/81/0091-0036 S 2.00