Frozen embryo transfer: the present practice and beyond

Area of Science:

• Reproductive Endocrinology
• In Vitro Fertilization (IVF)
• Endometrial Biology

Background:

• Endometrial preparation is critical for successful in vitro fertilization (IVF), particularly in postmenopausal women undergoing oocyte donation and for frozen embryo transfer (FET) cycles.
• Previous IVF attempts, ovarian hyperstimulation syndrome risk, or poor endometrial development necessitate optimized endometrial preparation strategies for FET.

Purpose of the Study:

• To evaluate the efficacy of letrozole-induced ovulation induction (OI) as a method for endometrial preparation in frozen embryo transfer (FET) cycles.
• To compare the success rates of letrozole-based endometrial preparation with gonadotropin-releasing hormone agonist down-regulation and natural cycle FET.

Main Methods:

• A prospective study involving 270 women aged 28-40 undergoing FET due to tubal factors.
• Participants were divided into three groups: gonadotropin-releasing hormone agonist down-regulation with hormone replacement therapy (n=100), natural cycle FET (n=55), and letrozole-induced OI for endometrial preparation (n=115).

Main Results:

• The letrozole OI group demonstrated significantly higher clinical pregnancy rates and live birth rates compared to the other two groups.
• This indicates a superior outcome for endometrial preparation using letrozole in FET cycles.

Conclusions:

• Letrozole-induced ovulation induction (OI) provides a viable, cost-effective, and easily administered option for endometrial preparation in FET cycles.
• This method shows promise for improving pregnancy and live birth rates in women undergoing FET.