Contraception. 2017 Apr 3. pii: S0010-7824(17)30100-2.

A survey regarding acceptability of oral emergency contraception according to the posited mechanism of action

Willetts SJ, MacDougall M and Cameron ST


Objective: The objective was to determine the acceptability to women of oral emergency contraception (EC) that works by inhibiting ovulation, preventing implantation or disrupting implantation, and also to determine the characteristics of women associated with the acceptability of each posited mechanism of action.

Study design: Women completed a self-administered, anonymous questionnaire asking whether they would consider using an EC pill based on each of three hypothetical mechanisms of action: inhibiting ovulation, preventing implantation or disrupting implantation. The questionnaire was distributed among women in Edinburgh, UK, (a) presenting for EC at a community pharmacy, (b) attending a clinic for insertion of intrauterine contraception (IUC) or (c) attending a clinic for an induced abortion. Descriptive analyses stratified women according to healthcare setting and personal characteristics. Univariable and multivariable analyses were used to establish factors which may predict acceptability of each EC pill's mechanism of action.

Results: Four hundred and nineteen out of 458 (91%) women responded to the survey. Overall, women reported that EC would be acceptable if it worked by inhibiting ovulation (89%), preventing implantation (83%) or disrupting implantation (75%). Among women seeking abortion, more would accept an EC pill which disrupted implantation compared to women seeking IUC (odds ratio, 2.19; 95% confidence interval, 1.30-3.69; p=.004). Based on multivariable analyses, factors associated with acceptability included previous use of EC, previously holding strong views against abortion and having had a previous abortion.

Conclusions: For each of the posited mechanisms of action, a majority of women surveyed would be willing to consider oral EC to prevent unintended pregnancy.

Implications statement: The scope of the study was limited, and further work on the views of women in the wider population is needed. This is important as the development of such drugs to prevent pregnancy is likely to raise political and ethical challenges, particularly in relation to disruption of implantation.

Comment: Although the authors conclude that this study had a limited scope, it is still important, since it shows (1) that there is no one kind of emergency contraception that is acceptable to everyone and (2) that, if the mechanisms are properly explained, for every woman there is a method that she will accept. (HMV)