A comparison among different methods of letrozole combined with gonadotropin in an antagonist protocol and high-dose gonadotropin ovarian stimulation antagonist protocol in poor ovarian responders undergoing in vitro fertilization.

Abstract

This study aimed at comparing the effects of different methods of letrozole combined with gonadotropin (Gn) and high-dose Gn ovarian stimulation in antagonist protocol. Retrospectively reviewed 220 poor responders from August 2012 to July 2014 at Peking University Third Hospital Reproductive Medical Center. Patients were divided into Group 1 (LZ 5mg for 5days sequentially overlapping with Gn cycles; n=60), group 2 (LZ 7.5mg for 3days sequentially with Gn cycles; n=60), and group 3 (high-dose Gn cycles; n=100). We compared the basic status of patients and clinical outcomes of the three groups. Basic characteristics of patients were comparable among groups. Group 1 had significantly higher LH levels on day 7 and hCG than Group 2 and 3 (P<0.05). Group 1 had significantly higher early LH elevation rate (>20IU/L) on the hCG day than Groups 2 and 3 (11.7 vs. 6.7 and 2.0%; P<0.05). The amount of Gn used in LZ groups was significantly lower than Group 3 (P<0.01). However, the clinical pregnancy rate and live birth rate were comparable among groups. In conclusion, the LZ/antagonist protocol is a cost-effective and patient friendly protocol, LZ 5mg for 5days sequentially overlapping with Gn protocol has comparable pregnancy outcomes, and LZ 7.5mg for 3days sequentially with the Gn protocol even has better clinical outcomes when compared with the standard GnRH antagonist protocol in poor responders. LZ 7.5mg for 3days sequentially with the Gn protocol appeared to have resulted in fewer improper LH surges and better outcomes than LZ 5mg for 5days sequentially overlapping with Gn in antagonist protocol.