Michael Rimmer


  • close

    ellaOne in practice

    Michael Rimmer, Victoria Sephton Brook Advisory Centre, Liverpool, UK - michael.rimmer@doctors.org.uk

    Objectives: To audit the day-to-day use of emergency contraception and compare the failure rates of levonorgestrel (previously the first line choice for emergency contraception) and ulipristal acetate (the new first line choice of emergency contraception) since implementation of new guidelines. Background: Unplanned pregnancy is a multifactorial problem affecting up to 7% of women each year. Despite emergency contraception (EC), many women still become pregnant and require termination of pregnancy (TOP). Increased effectiveness of EC and less reliance on TOP has positive benefits on a women’s social, mental and physical wellbeing. Studies looking at follicles close to ovulation have shown that levonorgestrel inhibits 14.6 % of follicles whereas ulipristal acetate inhibits 58.8% (Brache V et al, 2010). This suggests that ulipristal acetate works closer to ovulation, when risk of pregnancy is highest. This resulted in a change in guidance from the Faculty of Sexual and Reproductive Healthcare to offer ulipristal acetate (trade name - ellaOne) as first line of EC over levonorgestrel. Methods: An audit of women, receiving ulipristal acetate as 1st line (EC) was compared to a retrospective audit of women who received levonorgestrel as 1st line. Results & Conclusions: 662 women received ulipristal acetate of which 1 required a TOP; 1397 received levonorgestrel of which 5 required a TOP. This is shown below in the table with the failure rate.

    No. of women No. requiring TOP Failure rate Ulipristal acetate 662 1 0.0015106 Levonorgestrel 1397 5 0.0030157

    The odds ratio (of the failure rates) between ulipristal acetate compared to levonorgestrel is 0.50. (Calculation: Odds Ratio = 0.0015106 / 0.0030157 = 0.50091189). This demonstrates that the change in Faculty guidance is justified and that data from studies suggesting that ulipristal acetate is more effective than levonorgestrel is reflected in clinical practice.