Misoprostol for Medical Evacuation of Early Pregnancy Failure

Abstract & Commentary

Synopsis: In a pilot study, vaginal misoprostol was superior to oral misoprostol for uterine evacuation.

Source: Creinin MD, et al. Obstet Gynecol 1997; 89:768-772.

Studies have shown that many women who have experienced early pregnancy loss (blighted ovum, missed abortion, etc.) would prefer a medical alternative to surgery (suction evacuation) if one were available. Because misoprostol has been shown to be effective as an abortifacient in some settings, Creinin and colleagues performed a pilot study to determine whether oral misoprostol, 400 mg, or vaginal misoprostol, 800 mg, would be superior for medical uterine evacuation in cases of early pregnancy loss.

Twenty women were recruited for the study. Twelve were randomized to oral misoprostol and eight to vaginal. Each woman must have met the full set of study criteria prior to randomization. Once randomized, each participant was given her assigned medication and also received ibuprofen and acetaminophen with codeine tablets for pain. Each was given instruction in the use of a symptom log. Study participants returned 24 hours after receiving the medication. If a gestational sac was still present, the misoprostol dose was repeated. Those individuals who still had a gestational sac evident 24 hours after the second dose were offered suction curettage.

Three of the 12 women in the oral misoprostol arm of the study and seven of eight in the vaginal arm had successful medical resolution of their pregnancy. The difference between the success of the two arms was statistically significant. A majority of women experienced side effects. Fifty percent and 63%, respectively, of the women in the oral and vaginal groups experienced nausea; 25% and 13% experienced vomiting; and 42% and 38% experienced diarrhea. One subject required one dose of intramuscular meperidine for pain control.

Creinin et al conclude that vaginal misoprostol is more effective than oral misoprostol for medical uterine evacuation with an early pregnancy loss.


This is a small pilot study that accomplishes its stated purpose—to determine whether oral or vaginal misoprostol is superior for medical resolution of an early pregnancy failure with retained products of conception. Although Creinin et al conclude that vaginal administration of misoprostol was superior to oral, the observed difference may have been due to the use of a larger vaginal dose. In most studies, the investigators would use identical dosages, but Creinin et al chose different doses based on published studies of elective abortion with Misoprostol where these are the standard reported doses.

Unfortunately, Creinin et al did not include a control arm (expectant management). Although such an arm is not necessary for a pilot study with the objective as stated by Creinin et al, it would have been nice to know how many women would have spontaneously aborted. Indeed, in the Discussion section, Creinin et al reference a 1995 paper by Nielsen and Hahlin (Lancet 1995;345:84-86), in which 79% of the women in their study of expectant management had complete spontaneous emptying of the uterus within three days. There were enough differences between the current paper and this reference that a direct comparison cannot be made. However, it is clear that by the time pregnancy loss is identified by a clinician, many retained, failed pregnancies will spontaneously pass within a few days.

Clearly, a good deal more work needs to be done before we will know whether to offer patients misoprostol for retained products of conception. However, it is easy to foresee the day when we will offer such patients three choices: expectant management, medical management, or surgical intervention.