For Frozen Embryo Transfer Research Articles

Low utilization of extra embryos in donor oocyte in vitro fertilization cycles: an ethical dilemma to donor management

To explore outcomes of donor In Vitro Fertilization (IVF) cycles with regards to cryopreservation and utilization of extra embryos after fresh transfer. A database search was performed to identify all consecutive fresh donor oocyte cycles from January 1, 2000 to December 31, 2010 at a private fertility laboratory. Parameters analyzed included: number of oocytes retrieved, number of patients choosing embryo cryopreservation, number of patients returning for frozen embryo transfer (FET), and pregnancy outcomes. A total of 1070 fresh oocyte donor cycles were identified. Average number of oocytes retrieved was 16.9 ± 7.9, and average number of embryos transferred was 2.3 ± 0.96. Sixty-six percent of patients cryopreserved excess embryos following fresh transfer, and only 40 % of these patients ultimately returned for FET. Patients who conceived in their fresh cycle were much less likely to return for FET than those who did not (25 % v 65 %, p < 0.001), however chance of conceiving with FET was no different between these two groups (38 % v 38 %, NS). An unexpectedly low number of patients undergoing a donor oocyte IVF cycle will ultimately return to utilize extra embryos from their fresh cycle. This is concerning considering the high numbers of oocytes retrieved and the known complications from hyperstimulation, especially in light of the relatively high pregnancy rates associated with donor cycles. This raises concerns not only for donor management, but also raises ethical dilemmas when considering the large numbers of remaining embryos that will never be utilized.

Re-freezing blastocysts: a prospective randomized study comparing slow freezing and vitrification

OBJECTIVE: The potential to re-freeze blastocysts would be useful when surplus high quality blastocysts develop after thawing for frozen embryo transfer (FET). The objective was to compare the efficiency of slow freezing and vitrification for re-freezing blastocysts on survival rates and quality scores.

GnRH antagonist (cetrotide) instead of agonist to prepare recipients for embryo transfer: a prospective, randomized, controlled trial

OBJECTIVE: GnRH antagonists have replaced agonists in a significant portion of fresh IVF cycles worldwide because pituitary down regulation can be achieved while using fewer injections. This study examined the safety and efficacy of using an antagonist (Cetrotide), rather than an agonist, for uterine preparation of recipients for frozen embryo transfer (FET) and egg donation (ED) cycles.

Comparison of different luteal phase support protocols for frozen embryo transfer (FET).

Comparison of different luteal phase support protocols for frozen embryo transfer (FET).