Aghdas Ebadi - Department of Obstetrics and Gynecology, Faculty of Medicine, Mazandaran University of Medical Sciences
Sepideh Peivand - Department of Obstetrics and Gynecology, Faculty of Medicine, Mazandaran University of Medical Sciences
Hamed Jafarpour - ۲ Student Research Committee, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
Mina Abbaspour - ۲ Student Research Committee, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, Iran

Background and Aim : There is no reliable treatment for men with idiopathic infertility, but therelationship between severe sperm production and the ratio of estrogen to testosterone levels has beenshown. Aromatase is an enzyme that plays an important role in converting testosterone to estradiol andandrostenedione to estrogen. Aromatase inhibitors can increase testosterone and androgen productionwithout increasing the amount of estrogen in circulation. The aim of this study was to evaluate the effectof aromatase inhibitor letrozole on the male infertilityMethods : This pre- and post-quasi-experimental clinical trial was carried out on 41 men with an infertilitydiagnosis. The basic hormonal profile included FSH, LH, testosterone, and estradiol. The ratio oftestosterone to serum estradiol was also calculated and recorded. The sperm analysis was performed beforethe treatment and the seminal parameters were evaluated and recorded. Patients were then treated withletrozole 2.5 mg daily for 4 months. At the end of 4th months, the hormonal profile was studied and seminalanalysis performed and recordedResults : The levels of FSH, LH, testosterone, and estradiol, and the ratio of testosterone to estradiolincreased significantly after letrozole treatment. The sperm concentration, sperm motility, and spermforward motion significantly increased after letrozole treatment. Sperm morphology only lightly alteredConclusion : . The ratio of testosterone to estradiol levels in infertile men treated with aromatase inhibitorimproved and caused changes in sperm parameters. Letrozole may be used to improve sperm parameters ininfertile men with low serum testosterone to estradiol ratio.

male infertility, aromatase inhibitor, testosterone, estradiol, letrozole