Comparison of the effect of clomiphene citrate and the letrozole for ovulation induction in infertile women with polycystic ovarian syndrome

Anovulation is one of the most common causes of infertility. Different drugs in variousroutes are prescribed for its treatment. Clomiphene citrate (Clomiphene) and Letrozole are categorized as ovulation induction drugs. In the present study, the effect of Clomiphene and Letrozole, using step up method, is compared with each other in the treatment of infertility. In a randomized controlled clinical trial, 200 infertile patients with anovulation referred to infertility clinic of Bushehr University of Medical Sciences during 2008-2010 were studied in two equal groups. Informed written consent was obtained from all patients. For patients in each group, Letrozole or Clomiphene was prescribed from the third day of menstruation for five days in an increasing protocol of one, two and three tablets. Ovulation and endometrial thickness were evaluated by ultrasonography in 13th-14th days and pregnancy was confirmed by ßHCG. There were nosignificant differences regarding baseline demographic and fertility variables between two groups (p value> 0.05). Follicle formation (P value = 0.9), pregnancy rate (clomiphene 14.54% and letrozole 12.26%, P value=0.19), abortion rate and drug side effects were similar between two groups (p value> 0.05). In letrozole group, endometrial thickness was significantly lesser than clomiphene group. Estradiol level per follicle was higher in letrozole group (108.3+17.44) in comparison with clomiphene group (172.4+20.33) (P value< 0.0001). It seems that clomiphene and letrozole effectiveness in treating infertility due to anovulation are the same. Moreover, they are similar in ovulation induction and pregnancy rate. Considering patient compliance, cost and drug side effects one.