Pregnancy rates following the exclusive transfer of twice frozen twice thawed embryos using a modified slow cool cryopreservation technique.

PURPOSE: To determine the pregnancy rate following the exclusive transfer of twice frozen twice thawed embryos. MATERIALS AND METHODS: All day 3 transfers of exclusive twice frozen-twice thawed embryos were retrospectively identified over a 13-year time-period. The cryopreservation technique used a simplified slow cool freezing protocol. Embryos could have been originally cryopreserved at the 2 pronuclear or multi-cell stage. RESULTS: Survival rates were 83.3%. The live delivered pregnancy rate was 18.1% (15/83). The implantation rate was 13.1% (22/168). CONCLUSIONS: These data suggest that twice frozen twice thawed embryos should not be discarded but either transferred alone if they are the only embryos left, or mixed with frozen embryos that have never been thawed. Though the live delivered pregnancy rates are inferior to fresh embryo transfer the marked reduction in cost and avoidance of the risk of ovarian hyperstimulation justifies their transfer.

Oocytes from women of advanced reproductive age do not appear to have an increased risk of zona pellucida hardening.

PURPOSE: To test the hypothesis that very advanced reproductive age leads to an increased risk of zona pellucida hardening by comparing fertilization rates and rates of failed fertilization with conventional oocyte insemination vs intracytoplasmic sperm injection (ICSI). METHODS: Women aged > or = 45 were given the option of ICSI vs conventional oocyte insemination in circumstances where there was no male factor present. They were advised of the theoretical benefit of ICSI overcoming zona hardening but also advised that ICSI might lower pregnancy rates and is more costly. RESULTS: There were 364 cycles evaluated and 74% chose ICSI. The failed fertilization rates were similar--28.4% (66/232) for ICSI vs 26.5% (35/132) for conventional insemination. The fertilization rates were similar 56.0% with ICSI vs 50.9% with conventional oocyte insemination. CONCLUSION: Based on similar fertilization and failed fertilization rates in women aged > or = 45 undergoing IVF-ET, zona hardening does not appear to be a consequence of reproductive aging.

Effect of method of oocyte fertilization on fertilization, pregnancy and implantation rates in women with unexplained infertility.

PURPOSE: To determine if intracytoplasmic sperm injection (ICSI) offers an advantage over conventional oocyte insemination for women undergoing in vitro fertilization (IVF) and embryo transfer for unexplained infertility. METHODS: A retrospective seven-year review of outcome following IVF with conventional insemination vs ICSI for the category of unexplained infertility. The decision on which method of insemination to use was made by the couple after hearing pros and cons with the consulting physician. RESULTS: There was no difference in failed fertilization rates. However, the live delivered pregnancy rates were significantly higher for the group using conventional oocyte fertilization methods. CONCLUSIONS: Because of increased embryologist time and therefore increased expense to the patient it makes more sense to first try conventional oocyte insemination over ICSI for unexplained infertility, especially since the former results in a significantly higher live delivery rate

A comparison of the efficacy of intracytoplasmic sperm injection (ICSI) using ejaculated sperm selected by high magnification versus ICSI with testicular sperm both followed by oocyte activation with calcium ionophore.

PURPOSE: To determine in a couple where the male had globozoospermia with failed fertilization despite intracytoplasmic sperm injection (ICSI) if fertilization could be achieved by using high magnification ICSI or by oocyte activation by calcium ionophore. METHODS: Twenty eggs were retrieved and divided according to source of sperm, i.e., ejaculated by testicular aspiration or with donor sperm. Following ICSI the eggs were exposed to calcium inophore within one hour. The sperm were magnified 6300x in an attempt to find some sperm with evidence of at least some acrosome. RESULTS: None of the seven eggs inseminated by ICSI with ejaculated sperm or the seven inseminated with ICSI with testicular sperm fertilized even with attempted oocyte activation with calcium ionophore. However, four of the six oocytes that were inseminated with donor sperm did fertilize. None of the round-headed sperm showed any partial acrosome even using high magnification ICSI. CONCLUSIONS: It is possible that for successful fertilization with round-headed sperm there has to be at least enough acrosomal material to make some sperm-associated oocyte activating factor.