Oxytocin administration, instillation-to-abortion time, and morbidity associated with saline instillation

Among 4,069 healthy gravidas undergoing saline abortion, patients administered intravenous oxytocin had a significantly shorter instillation-to-abortion time (median, 25.5 hours) than did patients not administered oxytocin (median 33.3 hours). The instillation-to-abortion time was independent of the rate of oxytocin administration, which ranged from 1 to 4 U. per hour (17 to 67 mU. per minute), but was associated with the time at which oxytocin infusion was begun. When oxytocin infusion was started within eight hours after instillation, a shortened time from instillation to abortion was observed. Although oxytocin augmentation may result in a lower proportion of patients being exposed to the risk of infection associated with prolonged intervals from instillation to abortion, this potential advantage appears counterbalanced by an increased incidence of clinical consumptive coagulopathy associated with instillation-to-abortion intervals of less than 24 hours.