Management of failed prostaglandin abortions

Midtrimester abortion was induced in 529 patients by administration of the naturally occurring prostaglandins E2 and F2alpha as well as the 15-methyl analogs, 15-ME-PGE2 and 15-ME-PGF2alpha. Ten patients failed to abort with prostaglandin therapy, even in association with intravenous oxytocin, a failure rate of 1.9%. Two failures were related to uterine malformation; 1 patient had the pregnancy in a blind uterine horn, and the second patient was pregnant in one horn of a uterus didelphys. Five of the 10 patients who failed to abort during prostaglandin administration were subsequently found to have uterine distortion due to myomata uteri. When abortion induced by prostaglandin fails to occur within the expected time for the agent and technic employed, the presence of uterine malformation or abnormality should be considered. Evaluation with ultrasonography is indicated along with a repeat test to confirm the pregnancy. If the sonogram is suggestive of uterin malformation, a hysterosalpinogram should be obtained to determine if there is communication between the cervix and the gestational sac. If no communication is present, an intravenous pyelogram should be performed in view of the 90% correlation of urogenital abnormalities, and an exploratory laparotomy should be performed. When a communication exists between the cervix and the gestational sac, the 24 hours of uterine activity induced by the prostaglandin will have resulted in cervical changes so that the cervix can easily be dilated to either a 14 or 16 Hegar dilator and the conceptus can be removed in parts with minimal bleeding.