A Comparative Study between Clomiphene Citrate and Aromatase Inhibitor (Anastrozole) in Induction of Ovulation in Anovulatory Infertility

Clomiphene citrate (CC) has been used in the treatment of anovulatory infertility since 1962 [1]. There was discrepancy between ovulation rate of clomiphene citrate (60-90%) and pregnancy rate *10-40%. Also about 10-30% of the patients will be clomiphene resistant [2]. Preliminary evidence suggests that aromatase inhibitors may replace clomiphene citrate because of similar efficacy with a reduced side effect profile [3]. Aim of this study: Was to compare between a new aromatase inhibitor (anastrazole) and clomiphene citrate in induction of ovulation for anovulatory infertility. Type of the study: Randomized controlled clinical trial Subjects and Methods: The study was carried out on 66 female patients selected after fulfilling certain inclusion and exclusion criteria. The patient were equally and randomly assigned to one of two treatment groups; group 1 (C.C. group) was given (50mg tabs) 2 tablets (100mg/day). Group 2 (anas- trozole group) received (lmg tabs) one tablet twice daily (2mg/day). Each course was given for 5 days duration started from day 2 to day 6 of menstrual cycle. All patients were subjected to the following: full medical history, complete general and pelvic examination, hormonal profile on day 3 of cycle (FSH, LH, estrogen, testosterone, Prolactin, TSH, T3, and T4). Folliculometry was performed on day nine, eleven, and thirteen of the cycle. On day of HCG administra- tion; E2, LH and endometrial thickness were also measured. Results: The study revealed that there was statistically significant difference between responders of clomiphene citrate group and anastrazole group regarding number and size of mature follicles, serum E2 levels and endometrial thickness on HCG administration day. Mid luteal serum progesterone level was significantly higher in anastrazole group responders than clomiphene citrate responders group. There was also statistically significant difference between ovulation rate and pregnancy rate between both groups which were 48.5%, 15.2% for the first group and 75.8%, 36.4% for the second group. Conclusion: Anastrazole had lower number of mature follicle, thicker endometrium and lower level of E2 after ovulation induction when compared with clomiphene citrate in anovulatory infertility patients. So anastrazole can be alternative to clomiphene citrate because of better efficiency with reduced side effects.