Controlled ovarian hyperstimulation with sequential letrozole co-treatment in normo/high responders

Abstract

Objective: To investigate the effect of co-administration of letrozole in an ovarian stimulation protocol using recombinant FSH and GnRH antagonists for ICSI in normo/high responders.

Methods: Computerized data of 320 antagonist ICSI/ET cycles with or without letrozole were retrospectively analyzed. In 105 cases, letrozole (5 mg/day) was started at the second day of the cycle continued for 5 days. At the second day of letrozole, gonadotropins were added. The remaining 215 cases were stimulated with recombinant FSH only. In all cases on day 6, GnRH antagonist was started. Ovarian stimulation protocols with or without letrozole were compared for cycle outcome parameters.

Results: In cycles with letrozole, significantly lower gonadotropin consumption and lower peak estradiol levels were found. In cycles with letrozole, mean number of metaphase II and fertilized oocytes retrieved were significantly higher compared to cycles without letrozole. The pregnancy and clinical pregnancy rates were similar.

Conclusion: Should the number of oocytes retrieved being higher in letrozole group might indicate that letrozole might contribute to successful ovarian stimulation with a lower dosage of gonadotropins. Despite the lower peak estradiol levels, pregnancy rates being similar to other group also support the idea that letrozole can contribute to normal potential of implantation.

Chinese abstract

目的：为了探讨对于正常/高反应患者采用FSH和GnRH 拮抗剂进行卵巢刺激以行ICSI时，来曲唑的联合效应。

方法：回顾性分析了ICSI/ET拮抗周期中联合或不联合来曲唑的电脑存档病例共320例。105例于周期的第二天开始使用来曲唑，5mg/day，持续5天。在使用来曲唑的第二天开始加用促性腺素。剩余的215例仅使用重组FSH进行刺激。所有病例均在第6天开始使用GnRH拮抗剂。比较使用和不使用来曲唑卵巢刺激方案的周期参数。

结果：与未使用来曲唑的周期相比较，使用来曲唑时促性腺素的消耗量明显减少，雌激素高峰水平较低，获取的Ⅱ期卵母细胞和受精卵细胞的平均数量明显增多。妊娠和临床妊娠率相似。

结论：使用来曲唑可以获取更多的卵细胞可能预示来曲唑联合更低剂量的促性腺素就可以成功地刺激卵巢。尽管雌激素高峰水平稍低，但妊娠率相似表明使用来曲唑时植入潜力正常。

• Antagonist cycles
• COH with letrozole
• cycle outcomes
• IVF
• progesterone elevation

Declaration of interest

The authors declare that no actual or potential conflict of interest in relation to this article exists. This study has no financial support.