Successful pregnancies and deliveries after a simple vitrification protocol for day 3 human embryos

OBJECTIVE: To evaluate the efficacy and efficiency of freezing cleaved human embryos through vitrification. DESIGN: Clinical study of vitrification of human embryos. SETTING: Assisted reproductive technology centers. PATIENT(S): Thirty-six patients undergoing IVF-ICSI treatment whose surplus embryos were frozen. INTERVENTION(S): Two hundred fifteen surplus embryos vitrified, subsequently thawed, and transferred in natural or controlled cycles. MAIN OUTCOME MEASURE(S): Embryo survival rate after thawing and resultant patient pregnancy rate. RESULT(S): From the 215 vitrified and thawed embryos, 106 survived, with an overall embryo survival rate of 49.3%. The survival rate was higher when embryos were vitrified at the eight-cell stage compared with at the six to seven-cell and six-cell stages (79.2%, 39.7%, and 21.1%, respectively). On average, 2.9 +/- 1.2 embryos per patient were transferred, resulting in 11 pregnancies (30.5%), with an implantation rate of 10.4% per embryo transferred. CONCLUSION(S): Ultrarapid embryo freezing by vitrification of eight-cell stage embryos is a reliable method, as evidenced by high rates of embryo survival and pregnancy, making it a superior alternative to the conventional slow-cooling method.     

Effect of highly purified urinary follicle-stimulating hormone on oocyte and embryo quality

OBJECTIVE: To determine the effects of ovarian stimulation with highly purified urofollitropin on oocyte and embryo quality. DESIGN: Parallel randomized open-label clinical study. SETTING: Assisted reproduction centers. PATIENT(S): Two hundred sixty-seven infertile couples undergoing IVF/ICSI. INTERVENTION(S): All participants underwent standard down-regulation with GnRH analogue. One hundred thirty-three participants received highly purified urinary FSH and 134 controls received recombinant FSH. MAIN OUTCOME MEASURE(S): Primary end points were number of morphologically mature oocytes retrieved, embryo quality, and pregnancy and implantation rates. Secondary end points were: total number of days of FSH stimulation, total dose of gonadotropin administered, fertilization rate per number of retrieved oocytes, embryo cleavage rate, live birth and miscarriage rates, endometrial thickness and estradiol level on the day of hCG administration, cancellation rate, and incidence of moderate or severe ovarian hyperstimulation syndrome. RESULT(S): Pregnancy and implantation rates were nonsignificantly higher in the urinary FSH group than the recombinant FSH group (46.5% vs. 36.8% and 22.1% vs. 15.8%, respectively). The grade 1 embryo score was significantly higher in the urinary FSH group than the recombinant FSH (42.1% vs. 33.5%), and the live birth rate was nonsignificantly higher in the former group. CONCLUSION(S): Highly purified urinary FSH is as effective, efficient, and safe for clinical use as recombinant FSH.     

Zona opening with 308 nm XeCl excimer laser improves fertilization by spermatozoa from long-term vasectomized mice

Spermatozoa from long-term vasectomized mice have greatly reducedfertilizing ability in vivo and in vitro, which makes this auseful animal model for male factor infertility. The purposeof this study was to evaluate the 308 nm XeCl excimer laserfor opening the zona pellucida to enhance the fertilizationrate with spermatozoa from vasectomized males. Inseminatingzona-intact (control) oocytes with 5 x 10⁶ spermatozoa/ml resultedin only 6% fertilization and 33.3% development to the blastocyststage; zona-opened oocytes showed significant improvement with31.5% fertilization, 90% cleavage to the 2-cell stage, and 72.2%blastocyst formation. Out of the 130 oocytes in the experimentalgroup, zona ablation was performed successfully on 127 and onlythree were damaged. These results suggest that laser micromanipulationfor assisted fertilization potentially offers a simplified andprecise method for mechanical zona cutting.     

Modified vitrification of human pronuclear oocytes: efficacy and effect on ultrastructure

The efficacy of cryopreservation by direct plunging into liquid nitrogen (vitrification) of human pronuclear oocytes using open pulled straws with a super-finely pulled tip, as well as the ultrastructural changes caused by cooling and vitrification, were evaluated. Clinical and electron microscopic studies of cooled and vitrified oocytes were performed. Oocytes were cooled to 4 degrees C in the presence and absence of cryoprotectants, vitrified, warmed, cultured and transferred. Abnormally fertilized oocytes were examined by electron microscopy. Vitrified and warmed 2-pronuclear oocytes showed 71.1% survival rate and 83.3% developmental rate. One- and 3-pronuclear oocytes, after cooling without cryoprotectants (presumably non-viable), showed progressive swelling of mitochondrial smooth endoplasmic reticulum (SER). After vitrification, oocytes (presumably viable) showed the formation of large SER vesicles associated with mitochondria. The described protocol of vitrification of human pronuclear oocytes was shown to be effective in producing pregnancy. Normal ultrastructure after undergoing the described vitrification protocol was confirmed.     

Effect of cryoprotectants on the ultrastructure of cooled human pronuclear oocytes

Ultrastructural changes in human pronuclear oocytes were evaluated after cooling in the presence or absence of cryoprotectant.     

Gonadotropin treatment of an azoospermic patient with a Y-chromosome microdeletion

OBJECTIVE: To report on the treatment with recombinant FSH of an azoospermic normogonadotropic patient with a Y-chromosome microdeletion. DESIGN: Case report. SETTING: An assisted reproduction center. PATIENT(S): A 32-year-old patient with azoospermia. INTERVENTION(S): Histological testicular biopsy, Y-chromosome screening, FSH treatment, and intracytoplasmic sperm injection. MAIN OUTCOME MEASURE(S): Fertilization, embryo development, pregnancy, and delivery. RESULT(S): After 6 months of treatment with gonadotropins, a small number of spermatozoa were found in the patient's ejaculate and used for IVF, resulting in a successful twin pregnancy and the delivery of two healthy girls. CONCLUSION(S): In this study, treatment with gonadotropins promoted the spermatogenesis process and led to the production of spermatozoa in a normogonadotropic azoospermic patient.