Exploring women’s options: regimens of misoprostol with
mifepristone for early medical abortion
B. Winikoff (1), T. Aldrich (1), C. Shannon (1), E. Wiebe
(2), E. Schaff (3) Gynuity Health Projects, New York, USA (1);
University of British Columbia, British Columbia, Canada (2);
University of Rochester, New York, USA (3)
Background: Efficacy, side effects, and acceptability to
both the patient and provider have important impacts on how a medical abortion
regimen is used. Current clinical practice varies greatly with respect to dose
and route of administration of misoprostol following mifepristone for early
pregnancy termination, especially before 56 days LMP. There is no consensus on
an ‘optimal’ dose of misoprostol in this case, although research suggests
that women’s acceptability of the regimen may vary depending on the dose.
Similarly, systematic investigation into the merits of different routes of
administration of misoprostol in medical abortion is lacking. Emerging data on
the efficacy and safety of various medical abortion regimens, together with
insight into women’s own preferences, will have important implications for
service delivery.
Methods: We reviewed current evidence and research
regarding the efficacy, safety, and acceptability of different medical abortion
regimens.
Results: Findings from an array of recent and ongoing
trials suggest similar efficacy for selected medical abortion protocols at least
below 56 days LMP A recent three-arm randomized trial with 971 women found
comparable success rates and side effects for regimens of 200 mg mifepristone
followed by either 1) 200 mg oral misoprostol, 2) 400 mg oral misoprostol, or 3)
800 mg vaginal misoprostol. Preliminary findings from a current study comparing
vaginal and buccal administration of misoprostol following a 200 mg dose of
mifepristone also indicate similar success rates, with a trend towards greater
efficacy in the buccal group. These findings suggest that it may be feasible to
offer greater options for women who dislike vaginal administration of
misoprostol. The known pharmacokinetics and clinical correlates of vaginal, oral,
rectal, buccal, and sublingual administration of misoprostol for medical
abortion point to significant variability; however, studies suggest little
variation with respect to clinical efficacy for these different routes, at least
in the first part of the first trimester.
Conclusions: There appear to be a range of safe and
effective mifepristone-misoprostol medical abortion options. Where there are
small differences in the acceptability of different routes of administration,
the choice of route should ultimately be left to the woman. Such an approach
offers increased flexibility and patient autonomy in medical abortion provision
by taking into account the different personal and social factors that influence
women’s preference for a particular regimen; this in turn may improve overall
quality of abortion care. Future studies should continue to gather data on
patient experience and preference in medical abortion regimens.
