Background: Diminished ovarian reserve (DOR) is characterized by poor fertility outcomes even by using assisted reproductive techniques (ART). Recent data suggests that co-treatment by letrozole may improve ovarian response to FSH in poor responders and reduce gonadotropin dose required for ovarian stimulation. This study aimed to investigate the effect of letrozole administration combined with gonadotropin in patient with decreased ovarian reserve candidate for IVF.
Material and Methods: A clinical trial was conducted in the Infertility clinic, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Sixty-nine infertile women with DOR who have poor response to ovarian stimulation by gonadotropin-only regimen were recruited. The patients were treated by letrozole at 7.5 mg/day and FSH at 225 mg/day, started on the 2nd - 3rd day of the menstrual cycle and continued for 5 days. Ovitrell was given (at 250 mg) when at least 2-3 follicle reached 16-18mm (as matured follicle). AMH level, BMI and duration of infertility was recorded. The main outcomes measured as number of retrieved oocytes, number of oocyte II, endometrial thickness and pregnancy rate.
Result: Mean number of retrieved oocytes and oocyte II was 3.95 and 3.09 respectively. Mean endometrial thickening was 5.74 mm and rate of pregnancy was 19.7%. There was a statistically significant positive correlation between number of retrieved oocytes and AMH level (r=+0.27, P-value=0.028). There was a statistically significant negative correlation between number of retrieved oocytes and age (P value=0.04 ؛r= -0.253). Although, there was no significant correlation between number of retrieved oocytes and BMI (P value=0.2).
Conclusion: This study demonstrated that using letrozole combined with gonadotropin regimen in patient with DOR and poor response to gonadotropin-only protocol, improve response to ovarian stimulation. Number of retrieved oocytes is correlated with younger in age and higher level of AMH.