Repeat-breeder (RB) cows are a major source of economic waste due to their decreased fertility. Embryo transfer (ET) is an alternative tool to improve the fertility of RB cows. The aims of the present study were to evaluate the effects of recipient parity and the season on pregnancy rates following ET in RB Japanese Black beef cattle. Embryos were transferred nonsurgically to recipients, consis...

BACKGROUND This was a retrospective study to determine if diagnostic testicular biopsy followed by cryopreservation should be the procedure of choice for all patients with testicular failure. METHODS The first part of the study analysed 97 ICSI cycles scheduled with frozen-thawed testicular sperm for 69 non-obstructive azoospermia (NOA) patients. The second part focused on a subgroup of 32 pa...

although the mechanisms under which sex ratio is controlled in nature remain unknown, researchers have attempted to treat sperm in an effort to predetermine the sex of the offspring. the methods of sperm separation that have been repeatedly reported to isolate fractions rich in x- or y-chromosome bearing sperm are serum albumin gradient swim-up and flow cytometry. however, the ability of the se...

Embryos are conventionally selected for transfer based on the evaluation of the cleavage speed and extent of blastomere fragmentation. Here we examined whether the predictive value of these criteria, as indicators of the chance of embryo implantation, can be further potentiated by adding previously described criteria reflecting the regularity of pronuclear development. In a group of embryos sel...

OBJECTIVE During IVF, non-transferred embryos are usually selected for cryopreservation on the basis of morphological criteria. This investigation evaluated an application for array comparative genomic hybridization (aCGH) in assessment of surplus embryos prior to cryopreservation. METHODS First-time IVF patients undergoing elective single embryo transfer and having at least one extra non-tra...

Objectives: To compare the clinical outcomes of single fresh and frozen-thawed superior blastocyst transfer in patients for the first transfer. Methods: This study included 770 single fresh blastocyst and 639 single frozenthawed blastocyst transfers from January 2013 to January 2016. All the fresh and frozen-thawed embryo transfer was first transfer for the patients. The patients were divided i...

BACKGROUND The timing of embryo transfer (ET) after in vitro fertilisation (IVF) remains controversial, and there are no reliable guidelines available to prospectively identify which patients would benefit from either day-3 or blastocyst transfer. While blastocyst transfer is generally favoured over day-3 transfers, very few IVF patients get both in the same treatment cycle. CASE DESCRIPTION ...

Background: Vitrification and warming of blastocysts is an established procedure for the preservation of embryos during IVF. Vitrification is so successful that it allows for elective single embryo transfer (eSET) to be performed routinely, since the frozen embryos will be available with high implantation potential if the fresh embryo fails. Comprehensive chromosome screening (CCS) is also a pr...

In this work we analyzed the effects of three culture systems on developmental ability of bovine embryos in vitro produced with sexed sperm, the survival to vitrification (cryologic vitrification method) of such blastocysts, and their pregnancy rates after embryo transfer to recipients, both as fresh and after vitrification/warming. Finally, we measured the accuracy of the sorting protocol by a...

It should now be beyond doubt that blastocyst culture results in better pregnancy rate (PR). This calls for fewer embryos to be transferred, and indeed blastocyst culture is of most value when the intention is to put back one embryo at a time. The PR with one top-grade blastocyst is 45-65% in different studies. If two top-grade blastocysts are transferred, the PR usually does not differ, but th...