The overall increase in live births demonstrated by this study indicates that the effort and expense to culture embryos in a low-O(2) environment is justified. The study was registered at clinicaltrials.gov. NCT00708487.
SSS added to commercial HSA-supplemented embryo culture media resulted in an overall increase in implantation and live birth rates. It remains uncertain whether the use of human-derived blood products in culture media and the requirement for ultra-rigorous quality control measures make these findings applicable to the average IVF laboratory. Protein enrichment of media may significantly improve the blastocyst implantation rate, creating opportunities to transfer single blastocysts without compromising the live birth rate. The study was registered at clinicaltrials.gov. NCT00708383.
The ability to produce oocytes from genetically valuable, pregnant donors in a safe, repeatable manner would broaden the application of in vitro fertilization (IVF) procedures for beef and dairy cattle. The objectives of this study were to evaluate two gonadotropin treatment schedules for follicle stimulation of pregnant donor cattle and to determine the efficacy and safety of the repeated oocyte aspiration procedure from pregnant cattle. In Exp. 1, pregnant donors at 60 to 90 d of gestation were randomly allotted to three treatment groups. Cows in Treatment A received a total dose of 40 mg of FSH. Cows in Treatment B were administered a total of 20 mg of FSH, and females in Treatment C served as pregnant vehicle-treated controls. A group of luteal phase cows received a total of 40 mg of FSH and served as nonpregnant controls (Treatment D). Ultrasound-guided transvaginal oocyte aspiration was performed 12 h following the last FSH or saline injection. Following follicle aspiration, oocytes were matured for 24 h and then entered a standard bovine IVF procedure. Experiment 2 was conducted to determine the repeatability of this procedure on first trimester cows. Cows in Exp. 2 were selected (after a 20-d recovery period) from each of the three pregnant treatment groups in Exp. 1 and each given 40 mg of FSH before a second oocyte aspiration procedure. The number of follicles aspirated per cow in treatment groups receiving the high FSH dose treatment (40 mg of FSH total dose) was not different (Treatment A, Treatment D, and cows in Exp. 2).(ABSTRACT TRUNCATED AT 250 WORDS)
Most embryo culture media are still supplemented with proteins rather than with nonprotein macromolecules or recombinant protein products. HSA is probably the most common supplement followed by globulin-enriched preparations. Serum supplementation and Co-Culture of embryos belong to the past. Defined nonprotein or recombinant protein supplements are becoming a viable alternative during gamete and embryo manipulation procedures. Biological protein supplements are still preferred for any extended period of embryo culture. Understanding the goals and purpose of supplemented macromolecules in embryo culture media during each step of the laboratory IVF process should assist us in choosing the safest and most consistent macromolecule for each step, but also selecting a product that has the capability of delivering the best clinical outcome. Each batch of biological protein supplement is unique, even if supplied by the same manufacturer. Each lot of protein supplement typically contains many lot-specific, potentially harmful, and unintended hormone and protein contaminants. Macromolecular embryo culture medium supplements should be identified as one of the highest risk factors in an IVF laboratory that may contribute towards clinical compromise. All efforts should be made to use a proven batch of supplement for as long as the expiration date will allow. The beneficial effect of more complex protein supplements is evident after the activation of the embryonic genome and probably due to the presence of growth factors. Lower live-birth rates due to suboptimum protein supplementation may be a direct result of the preferential loss of female embryos. When deciding on a culture system, thought should be given specifically to the interaction between the culture medium and the macromolecular supplement. Ready-to-use pre-supplemented culture media may be advisable over a more complex product if a comprehensive macromolecular quality management program is not feasible. However, the question remains as to whether the increasing simplification of embryo culture media supplements is ready for large-scale clinical use.
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