Morphological sperm defects analyzed by light microscopy and transmission electron microscopy and their correlation with sperm motility

OBJECTIVES: To compare sperm defects as assessed by light microscopy (LM) and transmission electron microscopy (TEM), and to correlate them with sperm motility. METHODS: A cohort of 40 male partners of infertile couples was selected. Group 1 (n = 31) included subjects with motility >5 and <50%, group 2 (n = 9) included those with motility <5% and the control group consisted of 10 normospermic subjects. Semen analysis of morphological parameters was carried out by LM and TEM. RESULTS: A linear correlation between LM and TEM regarding head defects and excess residual cytoplasm (r = 0.87 and 0.90) was found, whereas there was a poor correlation between tail and midpiece anomalies (r = 0.46 and 0.21). No significant variations were detected by LM and TEM regarding sperm head defects and excess residual cytoplasm, whereas TEM showed a significantly greater percentage of tail and midpiece alterations compared with LM in groups 1 and 2, as well as controls (P < 0.05). The microtubular pattern '<9 + 2' represented the most frequent axonemal morphological alteration. CONCLUSIONS: TEM might represent an additional diagnostic tool in the presence of severe sperm hypomotility or absence of motility.