A randomized comparison of different hormone replacement protocols for thawed blastocyst transfer

Background There are no randomized controlled trials evaluating the pregnancy rates after thawed blastocyst transfers in patients treated with various hormone replacement regimens. Methods A prospective randomized controlled trial was conducted to evaluate the outcomes in three different hormone replacement protocols for thawed blastocyst transfer. A total of 330 women (median age 38.2 years) who were undergoing IVF at our clinic were enrolled. Results Serum estradiol (E2) levels were 267.71 pg/ml in Premarin group, 391.22 pg/ml in Estrogel group and 495.12 pg/ml in Estrana tape group. Therefore, serum E2 levels in Estrana tape group were higher than those of the other two groups (P<0.01). The pregnancy rate in the Estrogel group was higher than that in the Premarin group (30.0% versus 17.3%, P=0.026, odds ratio 2.05, 95% confidence interval: 1.09–3.87). Furthermore, the pregnancy rate in the Estrana tape group was higher than that in the Estrogel group (43.6% versus 30.0%, P=0.036, odds ratio 1.81, 95% confidence interval: 1.04–3.14). Conclusion The serum E2 levels contributed to differences observed in the pregnancy rate among the three different protocols. Thus, Estrana tape has an advantage as a hormone replacement protocol for thawed blastocyst transfer.