Successful pregnancy following replacement of embryos previously refrozen at blastocyst stage: case report.

We present the first reported clinical pregnancy following transfer of embryos that had been subjected to two freeze-thaw cycles: the first at day 3 after insemination, and the second after culturing to the blastocyst stage. A 25-year-old woman undergoing IVF treatment for male factor infertility opted for intracytoplasmic sperm injection (ICSI). ICSI treatment resulted in the successful production of 19 early cleavage embryos, all of which were frozen. After thawing, the embryos were cultured to the blastocyst stage. Thereafter, the blastocysts were refrozen and again thawed prior to embryo transfer. Embryos surviving a day 3 freeze-thaw cycle developed to the blastocyst stage and survived the second freeze-thaw cycle. Successful clinical pregnancy resulted following two sequential freeze-thaw cycles. This finding shows that it is possible to refreeze supernumerary blastocysts for subsequent transfer.

Comparison of cryopreservation outcome following intracytoplasmic sperm injection and conventional in vitro fertilization.

PURPOSE: Our purpose was to compare the success rate of transferring frozen-thawed embryos generated from either intracytoplasmic sperm injection (ICSI) or conventional in vitro fertilization (IVF). METHODS: A retrospective review of all frozen-thawed embryo transfer (ET) cycles between January 1995 and April 1997 was performed. There were 83 and 204 transfer cycles of frozen-thawed multicellular embryos generated from conventional IVF (group A) and ICSI (group B), respectively. The survival rate of frozen-thawed embryos and the outcome following ET in both groups were assessed. RESULTS: The groups did not differ in age (31.7 +/- 4.6 and 30.6 +/- 6.0; mean +/- SD) or number of embryos transferred (3.5 +/- 1.1 and 3.8 +/- 1.3 for groups A and B, respectively). An acceptable pregnancy rate per ET was achieved in both groups, but the rate was significantly higher (P = 0.04) for group A than group B, 32.5 and 20%, respectively. Group A included frozen embryos of a higher quality than those of group B, but the proportion of embryos surviving after thawing was significantly higher for group B than group A (92.5 and 85.6%, respectively; P = 0.0004). The abortion rate did not differ between the two groups: 22 and 26.8% for groups A and B, respectively. CONCLUSIONS: Although an overall high pregnancy rate was achieved following frozen-thawed ET, it was lower for cycles in which embryos had been generated from ICSI. This difference may be attributed to a lower prefreezing embryo quality in the ICSI group. Embryos originating from ICSI were not vulnerable to cryopreservation and, when implanted, resulted in a comparable abortion rate to thawed embryos of conventional IVF.

Experimental neoplastic spinal cord compression: effect of ketamine and MK-801 on edema and prostaglandins.

Excitotoxin-induced neural tissue damage is mediated through specific receptors. We studied the in vivo effect of two selective N-methyl-D-aspartate receptor antagonists on the compressed spinal cord segments of rats harboring a thoracolumbar epidural tumor. The effect of a single intramuscular treatment with either MK-801 (3 mg/kg) or ketamine (110 mg/kg) given at the onset of paraplegia was evaluated 30 hours later. In saline-treated control animals, significant increases in water content, prostaglandin E2, and 6-keto-prostaglandin F1 alpha were evident. Treatment with either agent resulted in a normal water content in the compressed segments but had no effect on prostaglandin synthesis. Evaluation of the effect of treatment on the course of the disease required dose reduction by 45% for ketamine and by 30% for MK-801, to avoid the excessive sedative effect. Treatment was started at the first appearance of neurological dysfunction (Grade 1) and continued to paraplegia (Grade 5). The mean time interval between Grades 1 and 5 was 2.1 +/- 0.3 days in saline-treated control animals, and it was not significantly altered by either ketamine or MK-801. Our study indicates that in the end stage of epidural compression, when ischemia is present, excitotoxins probably participate in the evolution of a cytotoxic edema. It is suggested that treatment initiated at the onset of paraplegia may still reduce the cytotoxic edema, but its potential clinical value requires further investigations.

Experimental neoplastic spinal cord compression: effect of anti-inflammatory agents and glutamate receptor antagonists on vascular permeability.

It has been demonstrated in paraplegic rats harboring an epidural neoplasm that an antiedema effect can be achieved by in vivo treatment with either steroidal or nonsteroidal anti-inflammatory agents or by glutamate receptor antagonists. The effect of these treatments on vascular permeability of the normal and compressed spinal cord was quantitated by the Evans blue dye technique. Tumor-free and tumor-bearing rats were assigned randomly for treatment as follows: 0.5 ml of saline or three doses at 12-hour intervals of either dexamethasone (5 mg/kg), methylprednisolone (30 mg/kg), indomethacin (5 mg/kg every 24 hours), or a single dose of either ketamine (110 mg/kg) or MK-801 (3 mg/kg). Treatment was given at the onset of paraplegia, and the animals were killed after 30 hours. In tumor-bearing rats in the early symptomatic stage, extravasation of Evans blue dye was 4.8 times greater than that of the normal cord (P less than 0.001) and at the onset of paraplegia it was 9.9 times greater (P less than 0.0006). Glucocorticoids and indomethacin reduced dye extravasation in paraplegic animals (P less than 0.01 and P less than 0.003, respectively), but the decreased permeability induced by ketamine and MK-801 did not reach the level of significance. In tumor-free control animals permeability was not changed by administration of either glucocorticoids or indomethacin but was significantly reduced by ketamine or MK-801 (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)