Table 2.
Summary of the Recent Studies Included in This Paper
| Study Type | Sample Size | Indication | Intervention | Outcome | |
|---|---|---|---|---|---|
| Badawy, 2008 (4) | Prospective, randomized | 220 | CC-resistant PCOS | Letrozole or anastrozole | No difference in pregnancy rate or miscarriage rate with either drug |
| Bayar, 2006 (28) | Prospective | 46 | Ovulatory infertility | CC vs letrozole | Comparable effectiveness |
| Atay, 2006 (29) | Prospective, randomized | 106 | PCO, ovulation induction | CC vs letrozole | Letrozole was associated with higher pregnancy rate |
| Kamath, 2010 (30) | Prospective | 36 | CC-resistant PCOS | Letrozole vs placebo | Letrozole treatment statistically increased ovulation rate |
| Abu Hashim, 2010 (31) | RCT | 250 | CC-resistant PCOS | Letrozole vs combined metformin-CC | Regimens equally effective for inducing ovulation and achieving pregnancy |
| Abu Hashim, 2010 (32) | RCT | 260 | CC-resistant PCOS | Letrozole vs LOD with 6-mo follow-up | Letrozole and LOD are equally effective for inducing ovulation and achieving pregnancy |
| Polyzos, 2008 (34) | Meta-analysis | 4 trials | PCOS | CC vs aromatase inhibitor | Significant advantage in pregnancy and delivery rates with AI compared with CC |
| Begum, 2009 (33) | Prospective, randomized | 64 | CC-resistant PCOS | Letrozole vs higher dose CC | Letrozole had better ovulation and pregnancy rate |
| Badawy, 2009 (••••) | Prospective, randomized | 280 | Unexplained infertility | Letrozole + FSH vs CC + FSH | No advantage of letrozole |
| Samani, 2009 (37) | Prospective | 64 | Unexplained infertility | CC→2 washout cycles→letrozole | Letrozole was associated with better follicular phase parameters |
| Fouda, 2011 (38) | RCT | 214 | Unexplained infertility | Extended letrozole vs CC | Extended letrozole found to have higher pregnancy rate per cycle and cumulative pregnancy rate |
| Abu Hashim, 2012 (39) | RCT | 136 | Endometriosis, no pregnancy 6–12 mo after laparoscopy | CC vs letrozole | No advantage of letrozole in overall pregnancy rate; total estradiol and number of follicles higher in CC group |
| Badawy, 2009 (35) | RCT | 796 infertile women and 200 spontaneous pregnant women | Safety | CC vs letrozole vs spontaneous pregnancy | Safety of drugs for both mother and fetuses was documented |