Evluation of Acrosome on Papanicolaou-Stained Sperm and its Relationship to the in Vitro Fertilizing Capacity of Human Spermatozoa

Abstract

Papanicolaou-stained sperm smears from 1150 ejaculates evaluated from infertility clinic patients and 166 ejaculates in an in vitro fertilization program were studied for the presence of acrosomal abnormalities. Morphologically, a normal acrosome was defined as a sperm having a ratio of 1:1 to 2:1 between the acrosome and postacrosomal part in an oval or round, uniformly shaped head. Acrosomal abnormality was identified in at least a few of the spermatozoa in all the ejaculates (range 8-98%) and appeared to be closely related to normal sperm morphology (r±0.85). A significantly higher (p < 0.01) correlation (r±0.31) was noted between the presence of normal acrosome and in vitro fertilizing capacity of spermatozoa as compared to other standard semen characteristics. Acrosome can be identified on Papanicolaou-stained smears, and since it appears to be related to fertility it may be beneficial to evaluate the acrosome morphologically during routine semen analysis.

Key Words:

• Acrosome morphology evaluation.