Analyses of human sperm by motile sperm organelle morphology examination (MSOME): an intervariation study

Abstract

OBJECTIVE: To evaluate the motile sperm organelle morphology examination (MSOME) analysis after a time interval. DESIGN: Prospective study. MATERIALS AND METHODS: Two semen samples were obtained from 121 men. No clinical or surgical treatment was realized between the two observations. Spermatozoa were analysed at 8400x magnification by inverted microscope equipped with DIC/Nomarski differential interference contrast optics. A spermatozoon was classified as morphologically normal when it exhibited a normal nucleus as well as acrosome, post-acrosomal lamina, neck, tail and mitochondria. For the nucleus, the morphological state was defined by the form and content of the chromatin. The criterion for normality of nuclear form was a smooth, symmetric and oval configuration. Normal means for length and width were estimated as 4.75±2.8 and 3.28±0.20μm, respectively. In addition, the nuclear form was also considered abnormal if extrusion or invagination of the nuclear chromatin mass was detected. Chromatin content was considered abnormal if one or more vacuoles were observed to occupy more than 4% of the nuclear area. At least 200 motile spermatozoa per semen sample were evaluated and the normality percentage was determined. One examiner performed the entire study. Normal form percentages were treated as a continuous variable for analysis. The Wilcoxon test and the Spearman correlation test were used where appropriate. RESULTS: Mean percentages of morphologically normal spermatozoa were identical in the two MSOME analyses (2.0±2.7% vs. 2.0±2.6%, P>0.05). Regression analysis between the two samples revealed significant positive correlation for morphologically normal spermatozoa (r=0.56 95%CI:0.42-0.67 P<0.0001). CONCLUSIONS: The significant positive correlation and absence of differences between two sperm samples evaluated after a time interval with respect to normal morphology indicated that MSOME is stable. The present result supports the future use of MSOME as a routine method for semen analysis.