The use of nuclear transfer (NT) techniques to create transgenic offspring capable of producing valuable proteins may have a major impact on the pharmaceutical market. Our objective was to compare the in vivo developmental potential of NT embryos produced from the fusion of transgenic donor cells with cytoplasts prepared from either FSH-stimulated ovaries or nonstimulated abattoir-derived ovaries. Donor cells were prepared from a transgenic fetus carrying the gene for human antithrombin III as a marker and used within four to eight subpassages. Cells were serum deprived for 4 days prior to cytoplast transfer. Oocytes were enucleated by removing the metaphase plate using a DNA stain and epifluorescent illumination. Donor cells were fused to enucleated oocytes by electric pulse and then chemically activated. There was no difference in the number of transferable embryos produced from cytoplasts of FSH-stimulated ovaries or from the fusion of cytoplasts from abattoir ovaries, nor was there a difference in the number of pregnancies established per recipient with either treatment. All pregnancies from both groups culminated in the births of healthy female kids (five total). To our knowledge, this is the first report of cloned goats produced from NT using cytoplasts derived from abattoir ovaries.
Objective-Given the importance of ET technique during assisted reproductive technology cycles, we evaluated the effect of embryo afterloading subsequent to placement of the ET catheter on pregnancy rates vs. a standard direct ET. Design-Retrospective cohort analysis. Setting-University-based assisted reproductive technology program.Patient(s)-Patients undergoing a fresh nondonor day 3 ET by a single provider over a 1-year period. Intervention(s)-None. Main Outcome Measure(s)-Clinical pregnancy.Result(s)-One hundred twenty-seven patients met inclusion criteria, and the overall pregnancy rate was 46.5%. There was no difference between the two groups with respect to age, basal FSH, or number of embryos transferred. The ET method used was at the discretion of the provider. There was no difference between the two groups in the presence of blood on the transfer catheter. However, there were significantly more transfer catheters with mucus contamination in the direct transfer group (25.58% vs. 5.95%). The clinical pregnancy rate in the group with ET using the afterloading technique was higher than in the direct ET group (52.4% vs. 34.9%). Conclusion(s)-There was a trend toward an increase in pregnancy rate when an embryo afterloading technique was used. A prospective randomized trial is needed to examine this issue. Technology reported an increase in live birth rates from 28% in 1996 to 32% in 2002 (1). This increase has been attributed to multiple factors including improved stimulation protocols (2-4), advances in embryology laboratory techniques (5), and improvement in ET techniques (6, 7). KeywordsEmbryo transfer is universally accepted as a crucial last step in any ART cycle. The importance of this step has been emphasized by the fact that different providers at the same institution may have disparate pregnancy rates after ET (8,9). Other variables affecting pregnancy include the ease of ET (7, 10, 11), presence or absence of blood on the transfer catheter (12), type of catheter used (13), technique used to perform the transfer (14-16), and experience of the physician (17).In the early 1990s, studies were first published on the use of a mock or "dummy" ET before the start of an IVF cycle (11,18). A mock ET allows the physician to choose the appropriate transfer catheter, measure the depth of the endometrial cavity, and anticipate potential problems at ET. However, a mock transfer remote from the actual ET is done under different circumstances and may not be reflective of actual conditions encountered on the day of ET. Sharif et al. (19) proposed to circumvent this problem by performing a mock ET immediately before the actual ET.To avoid additional trauma by the passage of two separate catheters, we began transferring embryos by an afterload technique, in which an empty catheter is placed at, or just past, the internal cervical os. The inner sheath is withdrawn, and a second inner sheath containing the embryos is passed. This gives the provider the benefit of an immediate mock transfer while minimizing mani...
Cryopreserved day-5 blastocysts have higher implantation rates and trend toward improved pregnancy outcomes compared with cryopreserved day-6 blastocysts. This suggests that embryo development rate may, in part, predict implantation and subsequent FBET outcomes, although embryos not achieving the blastocyst stage until day 6 still demonstrate acceptable outcomes.
PNMSs of 1, 2 or 3 do not correlate with live birth rates when assessing unique PNMS embryo transfers. In particular, previously considered poor (type 3) embryos can result in pregnancy with normal live birth rates. Whether type 4 embryos are compatible with normal development remains to be shown.
Infertility is a common disease, which causes many couples to seek treatment with assisted reproduction techniques. Many factors contribute to successful assisted reproduction technique outcomes. One important factor is laboratory environment and air quality. Our facility had the unique opportunity to compare consecutively used, but separate assisted reproduction technique laboratories, as a result of a required move. Environmental conditions were improved by strategic engineering designs. All other aspects of the IVF laboratory, including equipment, physicians, embryologists, nursing staff and protocols, were kept constant between facilities. Air quality testing showed improved air quality at the new IVF site. Embryo implantation (32.4% versus 24.3%; P < 0.01) and live birth (39.3% versus 31.8%, P < 0.05) were significantly increased in the new facility compared with the old facility. More patients met clinical criteria and underwent mandatory single embryo transfer on day 5 leading to both a reduction in multiple gestation pregnancies and increased numbers of vitrified embryos per patient with supernumerary embryos available. Improvements in IVF laboratory conditions and air quality had profound positive effects on laboratory measures and patient outcomes. This study further strengthens the importance of the laboratory environment and air quality in the success of an IVF programme.
Objective To determine whether a mandatory single-blastocyst transfer (mSBT) algorithm reduced multiple gestation rates without sacrificing clinical pregnancy rates. Design Retrospective review. Setting U.S. university-based assisted reproductive technology (ART) program. Patient(s) All women younger than 38 years undergoing their first ART cycle from 2009 to 2010 with ≥4 high-grade embryos on day 3 after oocyte retrieval (patients from 2009 were the “before” group, and patients completing ART under the mSBT policy in 2010 were the “after” group). Intervention(s) mSBT algorithm. Main Outcome Measure(s) Multiple gestation and clinical pregnancy rates. Result(s) Of the qualified patients, 136 women met inclusion criteria (62 from 2009, 74 from 2010). The baseline demographics were similar between the groups. Statistically significantly fewer blastocysts were transferred per patient in 2010 compared with 2009 (1.5 vs. 1.9). The clinical pregnancy rates before (67.7%) or after (63.5%) the mSBT policy were not statistically significantly different. Multiple gestation rates were statistically significantly reduced, from 43.8% (2009) to 14.6% (2010) after the mSBT policy was instituted. More patients from 2010 had ≥1 blastocyst cryopreserved compared with 2009 (52.9% vs. 30.6%). Conclusion(s) A novel single-blastocyst transfer algorithm reduced multiple gestation rates and improved cryopreservation rates without compromising clinical pregnancy rates in good-prognosis patients.
The SVSA is a reasonable option to retrieve sperm in wounded warriors or trauma patients with extensive genital injuries.
Models have been increasingly used in animal disease control policy in recent years, at both national and individual herd levels. This chapter reviews the strengths and weaknesses of some of these modeling techniques (epidemiological models, livestock databases, and risk models), assesses the prospects for future development of models, and provides indications of when it is likely that the use of models would be appropriate to assist decision making.
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