Background
First trimester miscarriage affects 20% of pregnancies. Medical management has a high degree of patient acceptance and does not increase the risk of infection. Mifepristone is an anti‐progesterone shown to improve outcomes when used in conjunction with misoprostol for first trimester abortion. However, there have been conflicting results when it has been added to treatment regimens for miscarriage.

Methods
We performed a retrospective cohort analysis of women presenting to the Acute Gynaecology Service of our tertiary referral centre for miscarriage management from December 2010 until December 2013. Patients given misoprostol alone were compared to those who received combination treatment with mifepristone and misoprostol. Primary outcome was failure of treatment determined by the need for repeat medical management or surgical curettage. Secondary outcome was need for hospital admission.

Results
A total of 281 women were treated from December 2010 to December 2013: 179 received combined mifepristone and misoprostol and 102 received misoprostol only. The primary outcome was significantly different between the two groups; 73% of women in the mifepristone and misoprostol group required no further treatment compared to only 56% of women in the misoprostol only group (P = 0.012). There were fewer hospital admissions, with 24% in the combined therapy group being admitted compared to 42% in the misoprostol only group (P < 0.001). Conclusion The addition of mifepristone to medical treatment regimens for first trimester miscarriage significantly decreased the need for repeat medical dosing and surgical curettage. Hospital admissions were also significantly decreased.