The effect of chromatin condensation (aniline blue staining) and morphology (strict criteria) of human spermatozoa on fertilization, cleavage and pregnancy rates in an intracytoplasmic sperm injection programme.

The main purpose of this study was to determine the possible relationship between chromatin condensation (Aniline Blue staining), the morphology of spermatozoa according to strict criteria, and the fertilization, cleavage and pregnancy rate in an intracytoplasmic sperm injection (ICSI) programme. A total of 60 patients were divided into two groups (27 versus 34) according to sperm stainability by Aniline Blue. The first group involved patients having a positive Aniline Blue staining test with 0-29% stained. The fertilization rate in this group was 60.8%, cleavage rate 54.4% and pregnancy rate 18.5%. In the second group in which > 29% spermatozoa were positively stained, the fertilization rate was 62.1%, cleavage rate 62.0% and pregnancy rate 35.3%. There was no statistically significant difference between the two groups. Furthermore, the influence of morphology according to strict criteria after Papanicolaou staining on successful fertilization, cleavage and pregnancy was studied in 85 patients who were divided into two groups according to the percentage of morphologically normal sperm. The fertilization, cleavage and pregnancy rates were 44.21, 63.37, and 39.47% respectively in the first group (< 4%), the corresponding values for the second group (> 4%) were 56.50, 46.04 and 21.21%. There was no significant correlation between the fertilization (P = 0.722), cleavage (P = 0.519) and pregnancy (P = 0.096) rates in either group. This study demonstrates that neither chromatin condensation (Aniline Blue staining) nor morphology could assess the fertilization potential, cleavage and pregnancy rate in an ICSI programme.