Второй доклад на конференции, представленный группой из Австрии, повторяет выводы сделанные данной группой в Лионе – ИМСИ значительно улучшает морфологию эмбрионов по сравнению с ИКСИ.
P-86
BLASTOCYST FORMATION AFTER INTRACYTOPLASMIC MORPHOLOGICALLY SELECTED SPERM INJECTION (IMSI) ACCORDING TO THE MORPHOLOGICAL INTEGRITY OF HUMAN SPERM NUCLEI
N. H. Zech, M. Bach, T. Neyer, A. Stecher, M. Zintz, P. Vanderzwalmen. Institute for Reproductive Medicine and Endocrinology, Bregenz, Vorarlberg, Austria.
OBJECTIVE: Selection of spermatozoa at high magnification is positively associated with pregnancy rates after day 3 embryo transfers for couples with previous failures of implantation. The aim of our work was to analyse if the existence of vacuoles in the nuclei of spermatozoa was negatively associated with the ability of embryos to develop to the blastocyst stage.
DESIGN: Morphological analysis of sperm pictures and correlation with embryo development to day 5.
MATERIALS AND METHODS: Before oocyte injection, a picture of each selected spermatozoon was taken at 12500_ magnifications under a Normarski interferential inverted microscope (Leica AM6000 Germany) equipped with a variable zoom lens. The embryos were cultured individually to day 5 in Global medium (Lifeglobal). Following morphological analysis of each picture, the spermatozoa were classified into 4 grades (I-IV): grade I: free of any abnormalities, grade II: a maximum of two small vacuoles (<4% head surface) and normal head shape, grade III: at least one large vacuole (>4%) and normal head shape, grade IV: presence of large vacuoles and abnormal head shape.
RESULTS: From a total of 307 selected spermatozoa 5.0% were of grade I. The majority presented as grade II (61.5%) or grade III (28.0%). The remaining were classified as grade IV (5.5%). On day 3 a trend to low rates of good quality embryos (7–8 equal blastomeres, absence of fragmentation) was observed in oocytes fertilized with grade III and IV spermatozoa (31.4% and 23.5%, respectively) as compared to grade I and II (46.7% and 36.0%). On day 5 the blastocyst formation was directly correlated with the type of injected spermatozoa. Oocytes fertilized with grade I and grade II spermatozoa reached the blastocyst stage in 73.3% and 45.0%, respectively, out of which 46.7% and 25.4% were classified as good quality blastocysts. On the contrary, after IMSI with compromised sperm injection only 9.3% (grade III) and 0.4% (grade IV) of embryos developed to the blastocyst stage with 3.5% and 0.1%, respectively exhibiting good quality.
CONCLUSIONS: Even though we are able to sort out spermatozoa with abnormal nuclear shapes and sizes using conventional ICSI, IMSI shows the importance for selecting spermatozoa with few specific nuclear defects such as vacuoles. The existence of large vacuoles in the nuclei of spermatozoa reduces dramatically the proportion of embryos to develop to the blastocyst stage suggesting damage to the integrity of spermatozoa such as anomalies in sperm chromatin packaging.
Опубликовано в Fertility and Sterility, v. Vol. 88, Suppl 1, September 2007, S137
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