To evaluate the post-thaw survival and the pregnancy outcomes of vitrified human blastocysts, a retrospective analysis was performed. A total of 213 blastocysts were thawed and transferred to 81 patients with 83% post-thaw survival, 31% clinical pregnancy, and 23% implantation rate per embryo. The clinical application of blastocyst vitrification with the cryoloop technique is effective based on the post-thaw survival and the pregnancy outcome.

Objective: To study the effect of in vitro culture on the quality of human testicular sperm and the efficiency of intracytoplasmic sperm injection with in vitro cultured testicular sperm.Design: Clinical study.Setting: A private IVF center.Patient(s): Twenty consecutively seen IVF patients undergoing testicular biopsies for ICSI.Intervention(s): The testicular specimens were cultured in vitro for 24 hours and the isolated spermatozoa were microinjected.Main Outcome Measure(s): Preincubation and postculture sperm motility, and fertilization, implantation, and pregnancy rates after intracytoplasmic sperm injection.Result(s): Motility increased from initial nonmotile or twitching sperm to free motile sperm in 18 of 20 cases. The injection of in vitro cultured testicular sperm resulted in a fertilization rate of 58%, an implantation rate of 20%, and a pregnancy rate of 45%.Conclusion(s): A testicular biopsy procedure can be performed the day before egg retrieval. Despite the low initial sperm quality, a high percentage of the prepared testicular sperm showed increased motility after 24 hours of culture. The injection of in vitro cultured testicular sperm into matured oocytes resulted in fertilization, implantation, and pregnancy rates comparable to those obtained with ejaculated sperm.

OBJECTIVE:To study the effect of freezing on early stage embryos derived from intracytoplasmic sperm injection (ICSI) or from IVF. DESIGN:Prospective, controlled clinical study. SETTING:Private IVF center. PATIENT(S):Sixty-seven consecutive patients undergoing frozen-thawed embryo transfer cycles. INTERVENTION(S):Early stage embryos were frozen, thawed, and transferred. MAIN OUTCOME MEASURE(S):Post-thaw survival, implantation and pregnancy rates. RESULT(S):We noted an 88% post-thaw survival rate, an 18% implantation rate, and a 52% pregnancy rate in the ICSI group and 81%, 11%, and 25%, respectively, with conventional fertilization. CONCLUSION(S):Early stage embryos (either zygote or 2-4 cells) derived from ICSI can be frozen with confidence and higher post-thaw survival and pregnancy rates can be achieved when compared with those from conventional IVF.

Commercially obtained Buffalo rat liver (BRL) cells were grown in monolayer culture. The effect of BRL cell co-culture with assisted hatching on embryo development, implantation and pregnancy was investigated in a population of 200 'first-time' in-vitro fertilization (IVF) patients, subdivided into three groups according to the methods of fertilization [IVF; intracytoplasmic sperm injection (ICSI); ICSI/IVF]. Assisted hatching was performed on all embryos chosen for transfer. Following co-culture, the overall embryo quality, implantation rate and pregnancy rates were not significantly different from the controls. However, when grouped according to fertilization method, co-culture was found to have an impact on pregnancy and implantation rates in the group undergoing conventional IVF. Using co-culture with assisted hatching, we were able to achieve a 58% (38/65) clinical pregnancy rate with a 49% (32/65) live birth rate and a 26% (60/235) implantation rate. No changes in the pregnancy and implantation rates were apparent in ICSI or ICSI/IVF subgroups. This is the first prospective, randomly controlled study which reports the use of BRL cell co-culture for human IVF for a large number of patients undergoing IVF for the first time.

Objective: To define statistical thresholds for the number of Embryos to be transferred to achieve an optimal pregnancy rate and keep higher-order multiple conceptions (pregnancy with more than two fetal sacs with cardiac activity) within an acceptable limit.Design: A retrospective review of patient records.Setting: Private practice assisted reproductive technology (ART) facility.Patient(s): Seven hundred fifty-four consecutive patients who underwent IVF-ET from 1994-1996.Intervention(s): Embryo grading and score system used on day 3 of embryo transfer.Main Outcome Measure(s): Implantation, pregnancy, and multiple conception rates.Result(s): For women less than or equal to 35 years old, transfer of up to four poor-quality, two fair-quality, or two good-quality embryos is optimal to eliminate any risk of higher-order multiple pregnancies. Transfer of four poor-quality, three fair-quality, or two food-quality embryos is recommended for women 36 to 39 years old. In women who are greater than or equal to 40 years old, five embryos need to be transferred regardless of embryo quality.Conclusion(s): The mean cumulative embryo score can he used as a reference to determine on optimal number of embryos to transfer and to predict pregnancy outcome. (C) 1998 by American Society for Reproductive Medicine.

A study was undertaken to evaluate embryonic development and establish pregnancies with human embryos after in-vitro culture in two different systems. Treatment A consisted of culturing zygotes in serum-supplemented human tubal fluid culture medium (HTF). Treatment B consisted of culturing zygotes on a monolayer of bovine oviductal epithelial cells with HTF. At the time of embryo replacement, embryos in treatment B had 4.11 blastomeres present, which was greater (P < 0.05) than the 3.81 present for embryos in treatment A. In addition, the cellular fragmentation rate for treatment A embryos was 1.10, which was greater (P < 0.05) than the fragmentation rate of 0.38 for embryos within treatment B. The incidence of ongoing pregnancy was higher after replacement of co-cultured embryos (treatment B) (43%) than replacement of conventionally cultured embryos (treatment A) (29%). The implantation rate per embryo increased (P < 0.05) from 11.5 to 18.4% after co-culture. In treatment B the proportion of 'spare' embryos developing to expanded blastocysts was 58.5%, which was greater (P < 0.05) than the blastocyst development rate of 29.3% observed for embryos within treatment A.