Backround: Ovulation is the central event in the reproduction cycle. Anovulatory dysfunction is a common problem and is responsible for about 40% of female infertility. Polycystic ovarian syndrome (PCOS) with abnormalities in the metabolism of androgens and estrogen and in the control of androgen production remains one of its leading causes .Polycystic ovary syndrome (PCOS) is a common multisystem endocrine disorder in women, with long-term health consequences
Objectives: Comparing the efficacy of Letrozole and Clomiphene citrate, as a first line treatment for induction of ovulation in cases of polycystic ovary syndrome.
Patients and Methods: This study was randomized comparative study involving 100 Egyptian women having polycystic ovary syndrome attending Al-Azhar University Maternity hospital (Sayed Galal/ Infertility outpatient clinic, And 6th October Health Insurance Hospital). During the initial visit, anthropometric measurements and baseline investigations were performed. Patients were randomized to 5.0 mg Letrozole daily (50 Patients) or 100 mg Clomiphene citrate (50 Patients) from the third until the eighth day of menstruation. Serial transvaginal scans were performed to see the dominant follicles, endometrial thickness and number of follicles. Transvaginal scans were performed serially to look for evidence of ovulation.
Results: The difference between Letrozole and Clomiphene citrate for ovulation rate was 44 (88%) versus 30 (60%) respectively. Patients taking Letrozole exhibited a mean endometrial thickness (ET) at mid cycle of menses (Day 11-D14) of 9.2 mm (SD 2.37) versus 8.4 mm (SD 1.61) for patients taking Clomiphene citrate, and these differences were statistically significant. In terms of pregnancy rate, Letrozole facilitated pregnancy induction in 19 patients (38%) versus 8 patients (16%) for Clomiphene citrate, which was statistically significant. More dominant follicles exhibiting a mono-follicular morphology were observed in patients treated with Letrozole compared to patients treated with Clomiphene citrate, with a mono-follicular dominant follicle observed in 23 (46%) versus 14 (28%) patients respectively.
Conclusion: Letrozole provided a more efficient stimulation compared to Clomiphene citrate in terms of ovulation induction, thickening of the endometrial lining and achievement of a successful pregnancy.