Progesterone levels on the day of human chorionic gonadotropin do not predict pregnancy outcome from the transfer of fresh or cryopreserved embryos from the same cohort

Objective: To analyze the differences in pregnancy rates (PRs) from the transfer of fresh and cryopreserved embryos from the same cohort of oocytes based on serum P levels on the day of hCG administration and the day after. Design: Retrospective analysis. Setting: Infertility patients stimulated for IVF-ET in an academic center. Patient(s): Three hundred thirty-three patients with fresh transfer and at least one transfer of cryopreserved embryos from the same cohort of recruited oocytes. All stimulations were down- regulated with a GnRH agonist in a long protocol before gonadotropin stimulation. Main Outcome Measure(s): Clinical PR. Result(s): The clinical PR in fresh cycles was 24% for the P ≤ 0.9 ng/mL group (group A; conversion factor to SI unit, 3.18) and 34% for the P > 0.9 ng/mL group (group B). Group B patients were younger, received fewer ampules of gonadotropins, had higher peak E₂ levels, and had more mature oocytes. There were no significant differences in the P levels on the day of hCG between patients who conceived in both fresh and cryopreserved cycles and any other combination of pregnancy outcome sequence. Conclusion(s): These findings suggest that serum P level cutoffs, on the day of hCG and the day after, as a means of making clinical decisions with respect to canceling the fresh transfer and cryopreservation of all embryos for future transfer should be questioned.