Efficacy of clomiphene citrate and letrozole in intrauterine insemination cycles

Abstract

Background: There are two commonly used drugs for ovulation induction, Letrozole and Clomiphene Citrate (CC). Aim of the present study was to evaluate the efficacy of Letrozole and CC in women undergoing Intrauterine insemination (IUI) and also to compare the effects of Letrozole and CC on total number of follicles, endometrial thickness, hormone levels and pregnancy rates. Methodology: In our study we recruited 63 patients attending KSHEMA IVF (Fertility and Reproductive Medicine Center) and OBG OPD, Justice K.S Hegde Charitable Hospital,at Deralakatte, Mangalore between January 2018 to June 2019. There were 35 patients in Letrozole group and 28 patients in CC group. Serial TVS was performed in both the groups until a mature follicle of diameter 18 mm is seen. Gonadotropin injections were added as per the requirement of the patients in each cycle following which hCG trigger was given and after 34-36 hours IUI was performed. Results: The endometrial thickness in CC group was found to be more than in Letrozole Group (8.21±1.64 VS 7.36±1.25), which was statistically significant, which correlates with another finding of the study ,i.e, pregnancy rates were higher in CC group than Letrozole group(63.5% Vs 37.5%). It was found in our study that number of follicles were more in Letrozole group than CC group(61.1% Vs 38.9%). The required mean dose of Gonadotropin was found to be less in Letrozole than in CC group (104.23±56.86 Vs 168.75±77.63). Conclusion: CC has been considered as the first line agent for ovulation induction since years. In our study, it was found that endometrial thickness was statistically more in patients who
received CC than Letrozole and pregnancy rates were higher in CC group. Also, number of dominant follicles was found more in Letrozole group. Patients in Letrozole group required less units of additional Gonadotropins.Hence we can conclude that Letrozole can be a better agent for ovulation induction, but CC might have a higher pregnancy rate than Letrozole.However it requires further study with larger sample size and sufficient study period so that the pregnancy outcomes can be studied