Precision measurements of dimensions, shape and mass density of spermatozoan heads in normal and subfertile human males

Abstract

Biometrical parameters of spermatozoan heads of normal and subfertile human males have been determined in smear preparations by means of the Dyson image-splitting eye-piece and interference microscopy. In the group of subfertility patients the mean spermatozoan head length L, the mean maximal head width B max and the mean projected head area A were significantly higher than in the normal group, whereas the mean dry mass density in the nuclear region was significantly lower. No difference in shape, as expressed by the shape factor L B max could be detected. The majority of the frequency distributions of the sample means of the separate parameters was skew in each group. Highly significant intercorrelations between biometrical parameters of the individual spermatozoan heads were found, with significant differences between the correlation coefficients in the donor (normal) and the subfertile group (Table I). After repeated drying and fixation with methanol spermatozoa from normal males were still capable to water absorption and swelling, whereas those from subfertile patients were not. The results of size measurements of spermatozoa in smears are systematically affected by the period of time that has elapsed between the moments of making the smear preparation and the taking of the measurements. (Table III). From advanced analysis of the cumulative frequency distributions of the pooled data of each group objective criterions for normal size ranges could be established (Table IV). The percentages of spermatozoa in the ranges of normal head length and those with normal head area were significantly lower in the subfertile group, whereas for deviating values the only significant difference was demonstrated for the percentage of “too large” head width.