Comparing Letrozole-Induced and Conventional Endometrial Preparation Protocols in Frozen-Thawed Embryo Transfer for Women Undergoing IVF

What this Trial Is About

This research aims to compare pregnancy and perinatal outcomes for women undergoing in vitro fertilization IVF treatments using different endometrial preparation protocols for frozen-thawed embryo transfer FET. It focuses on patients undergoing IVF or intracytoplasmic sperm injection ICSI and evaluates whether letrozole-induced endometrial preparation improves live birth and clinical pregnancy rates. The study also explores effects on spontaneous abortion, cycle cancellations, preparation duration, and clinic visits. Participants are randomly assigned based on menstrual cycle regularity to one of three groups letrozole-induced ovulation stimulation, natural cycle, or hormone replacement cycle. The letrozole group takes letrozole for five days starting day 3 of the cycle, followed by hormone injections and ultrasound monitoring until ovulation and embryo transfer. The natural cycle group monitors follicular growth with ultrasound before embryo transfer, and hormone replacement involves estradiol and progesterone administration before transfer. Embryos are transferred either 2-3 days after ovulation or 5 days later if blastocysts. Supportive medications continue for 14 days post-transfer. Women under 40 undergoing IVF with certain embryo availability are included. The study involves ultrasound and hormone tests to monitor follicle and endometrial development. Researchers measure outcomes such as live birth at 40-42 weeks gestation, clinical pregnancy at 5-7 weeks, and embryo implantation 14 days post-transfer. Safety and pregnancy progress are followed through the treatment and post-transfer periods. The study is conducted in a single center and participants undergo only one transfer cycle during the trial.

The Effectiveness of the Letrozole-induced Endometrial Preparation Protocol in Frozen-thawed Embryo Transfer (FET)