Use of Oral Misoprostol for Cervical Priming Before Hysteroscopy: a Randomized Comparison of Two Dosages

All patients admitted for hysteroscopy were offered participation in the study, and those choosing to participate were assessed according to the inclusion and exclusion criteria of the study protocol. The investigators included all non pregnant patients who were considered medically fit and scheduled for operative hysteroscopy, regardless of age or indication of the hysteroscopy. Patients with a positive history of vascular or coronary artery disease and patients using other products that could affect the consistency of the cervix such as local estrogen or laminaire were excluded from the study. To achieve a mean difference of 0.5 in the diffculty of dilation and a mean difference of 0.5 in the First Hegar with a power of 80% at 0.05 statistical significance, a sample of 163 patients in each arm is needed. However, the investigators patients pool did not permit to recruit more than 70 women so the investigators took it as a convenience sample of a total of 70 women that agreed to be recruited for the trial. An informed consent was obtained after explaining to the patients the benefit and the eventual risk or adverse effects associated with the medication. Studied factors were: age, parity, reason for the procedure, history of cervical dilation and history of cervical surgery.

Seventy closed and numbered envelopes, containing a capsule with either 200mcg or 400mcg of misoprostol were randomly distributed to these 70 patients. Each envelope was coded randomly and only the pharmaceutical department of the hospital knew the content of these envelopes and kept a list of their codes.

The misoprostol was administered by the floor nurse, per-os to the patient one hour before hysteroscopy with a small amount of water. The number on the envelope was noted by the nurse on the document relative to the patient. Hence, the patient, the physician performing the biopsy, the nurse and the research associate did not know the exact dose of misoprostol that was ingested by the patient.

Three physicians contributed to the study. Before beginning the procedure, the operator noted by pelvic examination the position of the cervix. He then noted the size/number of the first Hegar dilator used, the maximal dilation reached, the difficulty to dilate during the intervention (measured by a scale from 1 to 10), cervical injuries, bleeding or uterine perforation and the duration of the operation. A rigid hysteroscope (Storz, 27 F) was used for all procedures.

Adverse effects that could be related to misoprostol (uterine cramps, nausea, vomiting, diarrhea and fever), were reported before and up to 6 hours after surgery.