Critical reappraisal of embryo quality as a predictive parameter for pregnancy outcome: a pilot study.

AIM OF THE STUDY: Pilot study to analyse the efficacy and embryo morphology using a new human embryo culture medium (GM501) versus the conventional used medium (ISM1). METHODS: Over a four-month period, all patients at the Leuven Institute of Fertility and Embryology (LIFE) were -randomly allocated to have their embryos cultured in either the standard sequential culture medium ISM1 (control) or in a new universal medium (GM501) (study group). Primary outcome parameters were clinical pregnancy and live birth rate. The secondary outcome parameter was the correlation of embryo fragmentation rate with pregnancy outcome. RESULTS: We did not observe any differences between the ISM1 control group and GM501 study group with regard to fertilization, pregnancy, implantation rates, ongoing pregnancy, and babies born. The number of embryos with a minimal fragmentation rate (less than 30%) was significantly higher in the GM501 study group. CONCLUSION: Although a significant higher embryo fragmentation rate was seen in In vitro culture of embryos in GM501, pregnancy outcome results were comparable to those of embryos cultured in ISM1. According to our results the value of embryo morphological criteria as a parameter for pregnancy outcome should be examined and discussed again.

Intracytoplasmic sperm injection in the treatment of male subfertility.

OBJECTIVE: To evaluate the results obtained after intracytoplasmic sperm injection (ICSI) in couples with male factor subfertility. DESIGN: Retrospective analysis of results obtained after ICSI in the unit of in vitro fertilisation in a private centre for infertility. RESULTS: Application of ICSI in treatment cycles for male subfertility resulted in a fertilisation rate of 62%. An embryo transfer was done in 98% of the cycles, resulting in a 24% pregnancy rate/ET or 22% per cycle. CONCLUSION: ICSI is the first microfertilisation technique with reproducible high fertilisation rates in different centres and the method of choice in the treatment of severely impaired sperm quality. Although, up to now, no higher incidence of congenital malformations has been reported, except for sex chromosomal anomalies, careful genetic counselling is mandatory because of the risk of transmitting genetically defined male subfertility to the next generation.

Mitochondrial distribution after fast embryo freezing.

Mitochondrial distribution pattern after ultrarapid freezing in dimethylsulphoxide was assessed in human multipronucleate zygotes, 2-cell and 4-cell stage embryos using rhodamine 123. The mitochondrial distribution pattern was evaluated at 37 degrees C after a 30 min incubation in rhodamine 123 solution, 4 h and 24 h after thawing. Non-frozen human unfertilized oocytes, 2-cell and 4-cell embryos used as a control showed a homogeneous distribution of mitochondria throughout the cytoplasm, while there was sequestration of mitochondria from the cortex to the region surrounding the pronuclei in multipronucleate zygotes. Morphologically intact multipronucleate zygotes, 2-cell and 4-cell stage embryos after quick freeze-thawing showed the same mitochondrial distribution pattern found in the unfrozen controls. Mitochondria exhibited a typical severe aggregation (clumping) throughout the cytoplasm when non-viable single blastomeres or embryos at thawing were exposed to rhodamine 123. Our study indicates that quick freezing does not affect subcellular structures. The well-organized and specific mitochondrial distribution appeared still to be present after frozen storage, and subcellular structures seemed to be rather resistant targets for cryo-injury.

Subzonal insemination: a prospective randomized study in patients with abnormal sperm morphology.

OBJECTIVE: To evaluate in a prospective randomized study the outcome of subzonal insemination (SUZI) in patients with male subfertility. DESIGN: In a period of 7 months, 48 patients underwent IVF treatment for male subfertility reasons. Normal insemination and SUZI were performed on sibling oocytes. Patients were divided into three groups depending on the sperm morphology (strict criteria): group 1, 10% to 14%; group 2, 5% to 10%; group 3, 0% to 5%. SETTING: Private fertility center in Leuven, Belgium. MAIN OUTCOME MEASURES: The fertilization rates, cleavage rates, implantation rates, and pregnancy rates between the normally inseminated and the SUZI-treated group were compared. RESULTS: The fertilization rate with SUZI was significantly higher (32%) than after normal insemination (7%). The difference was striking in groups 2 and 3 (35% and 33% versus 11% and 4%). CONCLUSION: This study indicates that SUZI increases the fertility outcome in patients with male subfertility and that there is a marked difference in fertilization rate when morphology, using strict criteria, is < 10%.

Fluorescein diacetate assessment of embryo viability after ultrarapid freezing of human multipronucleate embryos.

OBJECTIVE: To assess embryo viability after ultrarapid freezing-thawing. DESIGN: We studied the fluorescence pattern of 35 ultrarapidly frozen-thawed multipronucleate human embryos exposed to fluorescein diacetate. SETTING: All the embryos were obtained from the Medical Center for Fertility Diagnostics and In Vitro Fertilization and Embryo Transfer at Leuven (Belgium), a private care center. PATIENTS, PARTICIPANTS: None. INTERVENTIONS: None. MAIN OUTCOME MEASURE: The fluorescence pattern was evaluated at room temperature after a 1-minute incubation in fluorescein diacetate solution, 4 hours and 24 hours after thawing. RESULTS: Healthy human multipronucleate embryos, when exposed to fluorescein diacetate, accumulated intracellular fluorescein and fluoresced brightly under ultraviolet light. On the other hand, embryos presenting submicroscopic cell membranes damage caused by different processes (e.g., high or low temperatures) lost the ability to accumulate intracellular fluorescein. All the ultrarapidly frozen embryos with normal looking blastomeres fluoresced brightly after a short exposure to fluorescein diacetate. CONCLUSIONS: Our experiments indicate an intact cell membrane permeability and an integrity of the intracytoplasmatic esterase enzyme activity of human embryos ultrarapidly frozen.

Survival and pregnancy outcome after ultrarapid freezing of human embryos.

Contrary to the belief that rapid cooling and thawing of mammalian embryos is detrimental to survival, it has been shown that under certain conditions mammalian embryos can survive rapid freezing-thawing. In this study, 237 human fertilized oocytes (93 pronucleates, 20 multipronucleates, and 124 cleaved embryos) were frozen for a period of 1 day to 7 months using the ultrarapid freezing system. After thawing, 94% of the embryos in the pronucleate group and 89.5% in the multipronucleate group showed normal morphological features, and 79% and 71%, respectively, started to cleave. Forty cleaved embryos were also frozen-thawed, but only 15 (37.5%) survived at thawing. Thirty-four frozen-thawed cleaved embryos were transferred to 20 patients during spontaneous cycles. Four patients became pregnant.