LATENT LABOR WITH AN UNKNOWN UTERINE SCAR

Objective: To determine if avoiding the augmentation of ineffective co ntractions ill women with unknown uterine scars would decrease the ris k of cesarean for protraction disorders, compared with awaiting the on set of spontaneous labor. Methods: Term gravidas with one or two unkno wn uterine scars in early labor were randomized to nonintervention (N = 101) and intervention (N = 96) groups, Nonintervention subjects were discharged if cervical change did not occur within 4 hours. Intervent ion subjects were admitted, Contractions that persisted for 4 hours wi thout cervical change were augmented with oxytocin. Results: Intervent ion subjects received oxytocin. significantly more often (82 versus 55 %, P <.001) and had a statistically significantly higher rate of uteri ne scar separation (5 versus 0%, P =.03). There was no difference betw een the two groups in length of active labor (4.0 versus 4.25 hours) o r incidence of cesarean delivery (16 versus 17%). Conclusion: The augm entation of ineffective contractions during latent labor in gravidas w ith an unknown uterine scar does not increase the rate of cesarean del ivery, but it is significantly more likely to result in uterine scar s eparations.