Uterine contractility in women whose fetus is delivered in the occipitoposterior position

摘要: Abstract Objective: Most fetuses in the occipitoposterior position rotate spontaneously after striking pelvic floor. The increased prevalence of prolonged labor, operative delivery, and oxytocin augmentation women with an fetal seems consistent decreased uterine contractility. We sought to test hypothesis that a persistent have inadequate intrauterine pressure. Study Design: Intrauterine pressure was measured prospectively electronically 94 whose labor pain controlled by patient-requested epidural analgesia. Eleven (12%) were delivered as position. In nested case-control study, these compared 22 who occipitoanterior matched for age, parity, gestational cervical examination at study enrollment, body mass index. measurements initiated during first stage continued throughout entire process. Women encouraged second period recording baseline contractility, push using standardized Valsalva maneuver once vertex reached +2 station. area under curve (integral) used estimate contractility expulsive performances. Results: Five (45%) group required delivery. average duration 91.4 ± 23.2 minutes 51.7 6.6 ( P =.04). Ninety percent oxytocin, 59% =.11). There no differences between groups either (integral mean SEM: [1685.3 194.6 mm Hg · s] vs [1700.8 128.9 s, =.98]) or stages (occipitoposterior [1952.6 186.5 [1740.8 104.3 =.46]). Further, there significant pushing performances (Valsalva maneuver: 2864.9 328.8 [2898.6 222.2 =.90]). Conclusion: do not lower levels immediately before labor. (Am J Obstet Gynecol 2003;188:734-9.)