Natural cycle cryo-thaw transfer may improve pregnancy outcome.

Objective: To compare natural vs. hormone replacement treatment (HRT) for cryo-thaw embryo transfer cycles in patients with frozen embryos from previous ART.

Design And Settings: Retrospective chart review of 164 patients (242 cycles) who underwent natural or HRT cryo-thaw embryo transfer between January 2002 and April 2005.

Efficacy of luteinizing hormone activity in patients undergoing in vitro fertilization and treated only with low-dose recombinant choriogonadotropin alfa (Ovidrel) in the late follicular phase.

Ten good prognosis patients underwent IVF with a new ovarian stimulation protocol using only 8 microg of recombinant choriogonadotropin and a GnRH antagonist starting at a 14-mm lead follicle. Six of the 10 subjects delivered and all had supernumerary embryos for cryopreservation.