ABSTRACT
The clinical usefulness of strict criteria1 for sperm morphology evaluation has been demonstrated by Kruger et al. in 19862 and thereafter has been confirmed in many publications3. However, even in the so-called P-pattern or poor-prognosis group (≤ 4% morphologically normal forms) of patients4, fertilization and pregnancies do still occur in some cases3. Therefore, efforts to develop more sensitive predictors of expected in vitro fertilization rates are continuously being published. Some of these predictors are based on sperm-function tests such as the Sperm Chromatin Dispersion Test5, the Sperm Chromatin Structure Assay6, and the Ubiquitin-based Sperm Assay7, while others have looked at a combination of semen variables, for example the Post-Wash Total Motile Progressive Cell Count8. Other authors have looked to refine certain existing semen variables, such as sperm morphology, by the use of more specific sperm morphology parameters viz. the Sperm Deformity Index9 or the spontaneous acrosome reaction as seen with Spermac staining10. In this regard, Menkveld et al.11 introduced the acrosome index (AI) as an additional tool in the prediction of expected in vitro fertilization rates. Menkveld et al.11 showed the AI to be a more sensitive parameter, compared with normal
rates of ≥ 50%; the use of the AI was found to be particularly useful in the P-pattern group of patients.
