The quality of spermatozoa has a direct influence on the fertilization and developmental competence of embryos. The aim of this work was to review the methods of spermatozoa morphology assessment, features of the normal spermatozoa and the reasons of their several abnormalities. Three methods can be used for the evaluation of spermatozoa morphology in the in vitro fertilization (IVF) laboratory: (1) light microscopy of stained spermatozoa, (2) motile sperm organelle morphology examination (MSOME) and (3) polarized light microscopy. The analysis of spermatozoa morphology includes the assessment of head, neck, midpiece and tail. Morphologically abnormal spermatozoa are categorized into subgroups according to the defects of the head, neck, midpiece and/or tail. Before IVF and intracytoplasmic sperm injection (ICSI), the quality of spermatozoa must be estimated exactly, because this has the high influence on embryo development. Therefore the analysis of the morphological parameters of spermatozoa using the light microscopy, MSOME, in combination with precise head birefringence detection using the polarized microscopy, could give the best fertilization rate and embryo quality after IVF and ICSI.
Part of the book: Spermatozoa