BACKGROUND Assisted hatching (AH) in fresh embryo transfer (ET) could be associated with increased implantation rates. However, very few prospective randomized studies have specifically addressed the issue of AH during frozen-thawed embryo transfers (FET) cycles, those that have reported controversial results. The aim of this study was to evaluate the benefit of an enzymatic zona pellucida trea...

In the present study, we used the sand cat (Felis margarita) as a somatic cell donor to evaluate whether cryopreservation of donor cells alters viability and epigenetic events in donor cells and affects in vitro and in vivo developmental competence of derived embryos. In Experiment 1, flow cytometry analysis revealed that the percentage of necrosis and apoptosis in cells analyzed immediately af...

The effect of modified vitrification was assessed on cellular development capability in mouse embryos cultured in vitro. In this study, 466 embryos (from zygote to morula stages) were vitrified then thawed embryos have been incubated for in vitro farther development up to blastocyst stage. Also, vitrification and thawing procedures were the same for all experimental groups. Mouse different embr...

OBJECTIVE This study was performed to compare the efficiency of slow freezing and vitrification based on survival, development to blastocysts, and cell numbers of blastocysts. Changes in embryonic gene expression in fresh and frozen-thawed embryos were also examined. METHODS Eight-cell stage embryos were collected from superovulated female BDF1 mice. The collected embryos were randomly divide...

This study is a long-term evaluation of the total pregnancy potential of cohorts of fresh and cryopreserved sibling embryos from in-vitro fertilization (IVF) cycles stimulated with either the gonadotrophin-releasing hormone analogue buserelin (BUS) (long protocol) or clomiphene citrate (CC) both in combination with human menopausal gonadotrophin (HMG). Therefore a retrospective analysis was per...

OBJECTIVE To evaluate the outcome of frozen-thawed ET using embryos previously biopsied for preimplantation genetic diagnosis during a fresh ET cycle. DESIGN Prospective evaluation. SETTING Assisted reproductive biology program. PATIENT(S) A 31-year-old, G4, P1, TAB1, SAB2 carrier of a balanced RT 45,XX der(14;21)(q10;q10) translocation. INTERVENTION(S) Preimplantation genetic diagnosis...

OBJECTIVE To report a live birth after transfer of cryopreserved pronuclear embryos in cryostorage for almost 20 years. DESIGN Case report. SETTING Academic IVF center. PATIENT(S) A 42-year-old female patient with low ovarian reserve receiving donated embryos. These embryos were the result of an anonymous donation from an infertile couple who had conceived during her IVF treatment. INTE...

During spring, summer and winter seasons, Sistani donor cows, with normal reproductive status, were superovulated and embryos were recovered non-surgically on day 7. Grade A blastocyst embryos were either transferred fresh (spring) or frozen (summer and winter). Recovered embryos during summer and winter were exposed to glycerol and frozen using conventional method. During spring season, recipi...

Background: The aim of our study was to compare the resulting from transfer of embryos that cryopereserved in cleavage stage after thawing and transfer of embryos after thawing and culture in sequentional media until blastocyst formation. Materials and Methods: In this prospective clinical study, we have evaluated 128 cycles in women undergone in vitro fertilization (IVF) or intracytoplasmic sp...

The use of cryopreserved human embryos in gene expression studies provides an additional source to the scarce embryos available for research. To validate their use we have implemented a quantitative RT-PCR to characterize the levels of the tuberous sclerosis, TSC2 gene in fresh and frozen-thawed human embryos. Frozen embryos were thawed using two different clinical protocols. In fresh embryos 9...