Gonadotropin Versus Gonadotropin/Letrozole Protocol in Previously Failed Antagonist Cycles in Patients with Low Prognosis

Objective: Letrozole is an aromatase inhibitor which has been used for ovulation induction. Our aim is to evaluate the effectiveness of adding letrozole to gonadotropins in the early follicular phase of gonadotropin-releasing hormone antagonist (GnRH-a) protocol in patients with poor ovarian response who had failed in the preceding GnRH-a cycle. Materials and Method: Ninety-eight patients with poor ovarian response who had previously failed GnRH-a cycle were included. Patients (n; 58) who were treated with letrozole plus gonadotropins (LzGA) were compared with patients (n; 40) who received gonadotropins (GT). The number of total oocytes retrieved, the number of MII oocytes and fertilized oocytes, fertilization and implantation ratios, the rate of cycle cancellation as well as clinical pregnancy and live birth rates Results: The LzGA group had a significantly shorter duration of GnRH-a stimulation and higher progesterone level at trigger day (p=0.005, p=0.049 respectively). Although letrozole administration demonstrated lower estradiol levels at trigger day and the total dose of gonadotropins used were lower in LzGA group, this was statistically non-significant (p=0.13, p=0.13 respectively). Conclusion: Adding letrozole to gonadotropins in GnRH-a protocol in patients with poor prognosis did not improve pregnancy outcomes. But it seems to decrease IVF costs by reducing the GnRH-antagonist and gonadotropin dosage.