Randomised controlled trial comparing the efficacy of same-day administration of mifepristone and misoprostol for termination of pregnancy with the standard 36 to 48 hour protocol

Abstract

Objective: To determine the efficacy of oral mifepristone followed by vaginal misoprostol 6 hours later compared with the standard 36- to 48-hour regimen for medical termination of pregnancy.

Design: Single centre, two arm, parallel, open randomised controlled trial.

Setting: Medical termination service at a teaching hospital.

Sample: Four hundred and fifty women undergoing medical termination of pregnancy at up to 63 days of gestation.

Methods: Eligible women were randomised to receive mifepristone 200 mg orally followed by vaginal misoprostol 800 micrograms either 6 hours (n=225) or 36-48 hours (n=225) later. All participants were invited to attend for a follow-up pelvic ultrasound scan within 7 days following the misoprostol administration. For those women in whom products of conception remained at the follow-up ultrasound scan, expectant management ensued with weekly follow-up ultrasound scans until the termination was complete. They could elect to undergo an evacuation of uterus at any stage following the scan. Those women with a nonviable gestation sac at the follow-up scan were offered a further dose of vaginal misoprostol 800 micrograms or suction termination of pregnancy. Women with a continuing pregnancy were managed with surgical termination.

Main outcome measure: Successful medical abortion defined as no requirement for medical or surgical intervention beyond the initial dose of misoprostol.

Results: One hundred and sixty-five women (79%) in the 6-hour group and 197 women (92%) in the 36- to 48-hour group had a successful termination at first follow-up ultrasound or presumed on the basis of other considerations (those not seen for ultrasound but deemed successful by negative pregnancy test, products passed on ward or long-term assessment of notes). Twenty-two women (10%) in the 6-hour regimen required up to three further ultrasound scans after 7 days following the mifepristone administration in order to ensure that the termination process was complete. None of these women required a suction evacuation of uterus. In the 36- to 48-hour regimen, ten (5%) women had up to two further ultrasound scans to confirm a complete termination without the need for a surgical evacuation of uterus. Therefore, the overall successful termination rate in the 6-hour regimen was 89% (187/210) compared with 96% (207/215) in the 36- to 48-hour regimen (relative risk=0.92, 95% CI 0.84-0.98). Repeat administration of misoprostol or surgical treatment was required in 23 women (11%) in the 6-hour group and 8 women (4%) in the 36- to 48-hour group. A viable pregnancy was found in five women (2%) in the 6-hour group and in three women (1%) in the 36- to 48-hour group.

Conclusions: Oral mifepristone 200 mg followed by vaginal misoprostol 800 micrograms after 6 hours is not as effective at achieving a complete abortion compared with the 36- to 48-hour protocol.