Two essential steps for a successful intracytoplasmic sperm injection: injection of immobilized spermatozoa after rupture of the oolema
Authors: Vanderzwalmen, P.; Bertin, G.; Lejeune, B.; Nijs, M.; Vandamme, B.; Schoysman, R.
Source: Human Reproduction, Volume 11, Number 3, March 1996 , pp. 540-547(8)
Publisher: Oxford University Press
Abstract:A total of 740 cycles of intracytoplasmic sperm injection (ICSI) were performed: 625 cycles when <6×105 total motile spermatozoa were harvestable from the ejaculate and 115 cycles in cases with a history of previous fertilization failure after classic in-vitro fertilization or subzonal sperm injection. An average of two pronuclei were observed in 63% of the injected oocytes, allowing 725 transfers of a maximum of three embryos (98%). Of 214 pregnancies initiated, 179 were established (25% of ICSI attempts). Because the fertilization rates from our initial 80 ICSI cycles were 2-fold less than those achieved previously, we changed the injection procedure and analysed, in 740 ICSI attempts, the importance of interfering technical factors and how to establish a successful ICSI programme, A remarkable change in the fertilization rate up to 68% (595 cycles) occurred when two steps in the injection procedure were performed well, i.e. immobilization of the spermatozoon and placement of the spermatozoon into the ooplasm after cytoplasmic aspiration into the pipette until oolema rupture. This immobilization, by touching the tail with the pipette, is mandatory for increasing the percentage of fertilization, even with totally non-motile spermatozoa (41%). Because aspiration of the cytoplasm is an invasive part of the ICSI procedure and influences the quality of the embryos, it is essential to reduce the amount of cytoplasm drawn into the pipette. This could be attained by using a spikeless injection pipette with the smallest possible internal diameter.
Document Type: Research Article
Publication date: 1996-03-01
- Human Reproduction features full-length, peer-reviewed papers reporting original research, clinical case histories, as well as opinions and debates on topical issues. Papers published cover the scientific and medical aspects of reproductive physiology and pathology, endocrinology, andrology, gonad function, gametogenesis, fertilization, embryo development, implantation, pregnancy, genetics, genetic diagnosis, oncology, infectious disease, surgery, contraception, infertility treatment, psychology, ethics and social issues. The highest scientific and editorial standard is maintained throughout the journal along with a rapid rate of publication.