Comparison Between Effect of Letrozole Plus Misoprostol and Misoprostol Alone in Terminating Non-Viable First Trimester Pregnancies: A Single Blind Randomized Trial.

Objective: To evaluate the effect of letrozole plus misoprostol to terminate non-viable pregnancies in first trimester compared with the use of misoprostol alone. Materials and methods: In a single-blind clinical trial, 128 women over 18 years old referred to Educational-Medical centers of Tabriz University of Medical Science (Tabriz, Iran), for abortion in first trimester of non-viable pregnancies, were randomly selected in two intervention and control groups using Rand list (version 1.2) software. To complete abortion both groups received 600 mcg of misoprostolorally. The intervention group received letrozole 10 mg daily for 3 days before receiving misoprostolorally. Complete abortion rate and the side effects of both groups were recorded. Results: Mean pregnancy age based on LMP in intervention group and control group were 7.74 ± 0.95 and 8.52 ± 1.29 weeks respectively. Complete abortion rate in the intervention group was 93.7%, and in control group was 68.7% which was significantly higher in intervention group (p = 0.001). Abdominal pain in the intervention group is also significantly lower than that of the control group (p = 0.013). Intervention group also had significantly lower duration of bleeding rather than control group (p = 0.006). Conclusion: Based on the findings of this study, letrozole pretreatment with misoprostol for first-trimester medical abortion can increase complete abortion rate significantly without increasing side effects compared to use of misoprostol alone.