Combined clomiphene citrate-metformin versus letrozole-metformin in achieving pregnancy among women: Polycystic ovary syndrome

Background: Polycystic ovary syndrome is one of the most common causes of anovulatory sub-fertility in women of reproductive age-group. The therapeutic procedure for women with polycystic ovary syndrome wanting to be pregnant is ovulation induction. Different medicines have been used based on individual signs and symptoms as the most effective one is not clearly evident. Clomiphene citrate and letrozole are the most common drugs used alone or in combination with metformin to achieve pregnancy in women with polycystic ovary syndrome. In this study, the efficacy of combined clomiphene citrate-metformin is compared with letrozole-metformin in achieving pregnancy among women with polycystic ovary syndrome. Methods: A retrospective study was performed among women with polycystic ovary syndrome attending Infertility Center, Kathmandu, Nepal from January 2013 to December 2015. Samples were randomly selected from list of the record in the treatment centre within the study duration. Total 146 cases with 73 each in clomiphene citratemetformin group and letrozole-metformin group were entered into the analysis. Participants had received metformin in combination with either clomiphene citrate (100 mg) or letrozole (2.5 mg) from day 3 to 5 of their menstrual cycle. Odds ratio, with confidence interval set at 95%, was calculated to compare the efficacy between two groups. Results: The pregnancy rate of clomiphene citrate-metformin was 54.79% and letrozole-metformin was 34.25%. Patients treated with clomiphene citrate-metformin were two times more likely to get pregnant [OR: 2.33, 95% CI: 1.19 – 4.54] than those treated with letrozole-metformin. Miscarriage rate was not found to be statistically significant. Conclusion: Clomiphene citrate in combination with metformin is more likely to be effective than letrozole with metformin in achieving pregnancy.