Objective: To determined the pregnancy rate of thawed embryo transfer during natural or controlled cycles using exogenous steroid a prospective randomize study form 1327 to 1378 in royan institute, 44 patients who were<35 years of age underwent 155 thawed embryo transfer.
Main outcome measure: Pregnancy and implantation rates per thawed embryo transfer cycle.
Material and method: Patients divided in two groups.
Group I: Patients who had irregular menses, and ovulatory problem used GnRH agonist and hormone replacement therapy protocol.
Group II: Patients who had regular menses, transfer was performed in a natural cycle 2 days after the LH peak or on day 17 of cycle.
Results: Semilar pregnancy rates were seen in natural cycle (5.9%) and programmed cycle (8%) the implantation rates were similar in the two methods of transfer cycles there were no significant difference in clinical or on going pregnancy rates in a natural or programmed cycle.
Conclusion: Transferring cryopreserved thawed pre-embryo in a natural or programmed cycle yielde similar pregnancy results.