Determining the Optimal Duration of Progesterone Supplementation prior to Transfer of Cryopreserved Embryos and Its Impact on Implantation and Pregnancy Rates: A Pilot Study.

in 2007 studied 49 frozen thawed blastocyst transfer cycles and found that clinical pregnancy rates, ongoing pregnancy, and implantation rates were higher when progesterone was given for 5 days before the transfer as compared to 6 days (60.9% versus 53.8%, 56.5% versus 50.0%, and 40.7% versus 30.0%, resp.), but the differences did not reach statistical significance ( p s > 0.05).

also in 111,027 other papers