Table 6.

Summary of randomized trials assessing the efficacy of letrozole

Study (reference number)	Intervention	Cohort of patients	Conclusion
[20]	Letrozole (2.5 mg) Vs CC	Infertile women undergoing Superovulation and IUI.	Similar endometrial thickness and pregnancy rates.
[21]	letrozole Vs CC as adjuvants to rFSH 41 patients	Superovulation before IUI in unexplained infertility	Better endometrial thickness with letrozole. Similar pregnancy rate
[22]	Letrozole Vs CC 74 patients	Polycystic ovary syndrome	Similar endometrial thickness and pregnancy rate
[23]	Letrozole (2.5 mg) Vs CC	Polycystic ovary syndrome	Better endometrial thickness and pregnancy rate with letrozole.
[24]	Letrozole Vs CC	Polycystic ovary syndrome	No advantage to the use of letrozole over CC as a first-line treatment for induction of ovulation in women with PCOS
[25,26]	Letrozole Vs CC	Superovulation before IUI in unexplained infertility	No superiority between letrozole and CC for inducing ovulation in women with unexplained infertility before IUI.
[27]	Letrozole Vs CC-gonadotropin	Superovulation before IUI in unexplained infertility	Letrozole is a good alternative to CC-gonadotropin.
[28]	Letrozole (2.5 mg) Vs CC 22 patients	superovulation in women with normal ovulation	CC is superior to 2.5 mg letrozole for superovulation induction in women with normal ovulation.
[29]	Letrozole (7.5 mg) Vs CC 46 patients	Polycystic ovary syndrome	Letrozole has better ovulation and PR in comparison to CC in patients with PCOS