GnRh Agonist Treatment Improves Implantation and Pregnancy Rates of Frozen-Thawed Embryos Transfer.

Objective: To study the effect of GnRh agonist administration prior to estrogen-progesterone preparation of the endometrium on the implantation rate in frozen-thawed embryo transfer (FET) cycles in infertile patients treated with IVF/ICSI.

Design: Prospective controlled study. Setting: Private center in Alexandria, Egypt. Patients: Patients undergoing frozen-thawed embryo transfer FET. Interventions: Patients were divided into two groups, A and B. Group A patients consisted of 110 patients (110 cycles) who received daily subcutaneous injections of 0.1 mg of the GnRh agonist triptorelin starting from the mid-luteal phase of the cycle preceding the actual FET cycle. The dose was reduced to 0.05 mg from the second day of the cycle when daily oral estradiol valerate 6 mg was also started. Daily vaginal supplementation of micronized progesterone 400 mg b.d. was started after 12 days when the GnRh agonist was also stopped. Frozen-thawed embryos were transferred on day + 1 of their chronological age and when the endometrium reached 12 mm in thickness. Group B consisted of 100 patients (100 cycles) who started daily estradiol valerate 6 mg administration from the second day of the FET cycle and followed the same regimen but without prior treatment with triptorelin. Main outcome measures: Implantation and pregnancy rates were compared among the two groups.

Results: There was a significant increase in implantation rate in the GnRh agonist group (group A) compared to the estrogen and progesterone only group (group B) (44.1 vs. 21.1 %; P = 0.002*). The pregnancy rate was also significantly higher in group A compared to group B (65.5 vs. 42 %, P = 0.013*).

Conclusions: GnRh agonist administration during endometrial preparation for FET increases the implantation and pregnancy rates.