PubMed · 10632437
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K Yakin, C Akarsu, S Kahraman. 2000. Cycle lumping or--sampling a witches' brew?. https://doi.org/10.1016/s0015-0282(99)00430-6
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BACKGROUND: In vitro fertilisation (IVF) and embryo transfer as treatment for male factor infertility is associated with lower fertilisation and pregnancy rates than for other indications. Since the late 1980s several assisted fertilisation techniques have emerged and have been rapidly developed to try to enhance results for couples with male factor infertility, or to help couples with severe male factor for whom conventional IVF was not possible. The technique of partial zona dissection (PZD) was developed to increase the probability that a sperm capable of fertilisation comes in contact with the oocyte. Although this method improved conventional IVF results, the improvement was only marginal and relatively large numbers of sperm are still required. This drawback applied less to the subsequent technique of subzonal microinjection of spermatozoa into the perivitelline space (SUZI). However, for all of these techniques fertilisation rates remained low, rates of polyspermic fertilisation were increased, and cases with a very limited number of spermatozoa in the ejaculate could still not be treated. The advent of intra-cytoplasmatic sperm injection (ICSI) of a single sperm (or sperm head or nucleus) into the oocyte appears to be an important breakthrough. OBJECTIVES: To investigate whether ICSI improves fertilisation and/or pregnancy rates in comparison to other fertilisation techniques. SEARCH STRATEGY: The Menstrual Disorders and Subfertility Group search strategy (see Review Group details) was used to identify trials that had compared ICSI with other infertility techniques, such as PZD, SUZI, conventional IVF and additional IVF. SELECTION CRITERIA: Trials were included if they compared the effects of these techniques on fertilisation and pregnancy outcomes. Only randomised studies were included in this review. DATA COLLECTION AND ANALYSIS: Ten studies met the inclusion criteria for this review. Eight studies compared ICSI with conventional IVF. One study compared ICSI with SUZI and one study compared ICSI with additional IVF. Data was extracted independently by two reviewers. Where relevant data was missing or unclear, the authors had been consulted. Male participants were classified according to their semen parameters, i.e. normal semen (concentration >20 million per ml, motility >50%, morphology >14%), borderline semen (concentration 10-20 million per ml, motility 30-50%, morphology 4-14% normal forms) and very poor semen (concentration <10 million per ml, motility <30%, morphology <4% normal forms). MAIN RESULTS: For couples with normal semen there is no evidence of a difference in fertilisation rates per retrieved oocyte or pregnancy rates between ICSI and conventional IVF. On the other hand, for fertilisation rate per inseminated oocyte, ICSI appears to result in better outcomes than IVF for normal semen. For couples with borderline semen ICSI results in higher fertilisation rates (all) than IVF. Couples with very poor semen will have better fertilisation outcomes with ICSI than with SUZI or additional IVF. REVIEWER'S CONCLUSIONS: There is evidence from this systematic review that fertilisation rates are significantly better with ICSI than IVF in couples with borderline semen. When the semen parameters are normal there is insufficient evidence of a difference in effectiveness between ICSI and IVF when retrieved oocytes were the unit of randomisation. However, there was a small but statistically significant increase in fertilisation rate when inseminated oocytes were the unit of randomisation. Total fertilisation rates were significantly reduced in ICSI cycles than IVF but there were no damaged oocytes in IVF cycles regardless of the semen parameters.
OBJECTIVE: To improve in vitro culture conditions and human embryo selection before transfer after IVF with intracytoplasmic sperm injection (ICSI). DESIGN: A controlled, randomized, prospective study. SETTING: University hospital-based IVF-ET program. PATIENT(S): Couples undergoing ICSI. INTERVENTION(S): Culture of human embryos in the presence of 1 mM or 5.56 mM glucose and metabolic measurements with the use of noninvasive microfluorescence assays immediately after ICSI to the time of transfer. MAIN OUTCOME MEASURE(S): Embryo development, implantation rate, and glucose and pyruvate uptake. RESULT(S): Fertilization rates, early embryo development, and implantation rates were not significantly different between 1 mM and 5.56 mM glucose. Pyruvate uptake was significantly higher during the formation of the pronuclei, at 15 +/- 0.7 and 11.4 +/- 1.3 pmol/embryo/h for fertilized and unfertilized oocytes, respectively. Pyruvate uptake did not correlate with cleavage stage or embryo morphology. However, during the second day of incubation, pyruvate uptake was significantly higher for the untransferred embryos of pregnant women compared with nonpregnant women, at 17.9 +/- 1.5 and 10.8 +/- 1.0 pmol/embryo/h, respectively. CONCLUSION(S): The increased level of pyruvate uptake during fertilization reflects the increased demand for energy necessary for the formation of the pronuclei. However, the metabolic measurements could not improve the selection of embryos with the best implantation potential. Finally, the reduction of glucose concentration in the culture medium failed to improve embryo viability.
OBJECTIVE: To evaluate the efficacy of zygote intrafallopian transfer (ZIFT) in terms of implantation and pregnancy rates in patients with tubal factor infertility and repeated implantation failure in IVF-ET cycles. DESIGN: Retrospective analysis of ZIFT cycles. SETTING: An IVF unit in a university hospital. PATIENT(S): Criteria for patient selection for ZIFT included at least four failures of implantation in IVF-ET cycles in which at least 3 embryos were replaced per transfer and a cause of infertility diagnosed as male, unexplained, or tubal factor with proof of one patient tube. INTERVENTION(S): Four to six zygotes were transferred by laparoscopy into the fallopian tube 24-26 hours after oocyte retrieval. MAIN OUTCOME MEASURE(S): Implantation and pregnancy rates were determined in 112 ZIFT cycles performed in 81 patients with repeated failure of implantation. Results were further stratified for patients with tubal factor (n = 15) and patients without tubal factor (n = 66). RESULT(S): The pregnancy and implantation rates for all ZIFT cycles were 35.1% and 11.1%, respectively. Pregnancy and implantation rates per cycle in patients with tubal factor versus patients without tubal factor were 26.6% versus 37.1% and 9.4% versus 11.4%, respectively. CONCLUSION(S): ZIFT can be considered as a mode of treatment for patients with repeated failure of implantation in IVF-ET and with tubal factor with proved patency of one tube.