TEM and FISH studies in sperm from men of couples with recurrent pregnancy loss

The role of the male partner in recurrent pregnancy loss (RPL) is not clear. In this study, semen characteristics of 22 men whose partners had experienced RPL were examined by light microscopy. Sperm morphology was analysed by transmission electron microscopy (TEM) and the data were mathematically elaborated to obtain numerical indices expressing the status of an ejaculate: the fertility index and the percentage of apoptosis, necrosis and immaturity. Sperm apoptosis and necrosis were also evaluated by annexin V/propidium iodide assay. To explore the status of meiotic segregation, fluorescence in situ hybridisation (FISH) with probes for chromosomes 18, X and Y, was applied directly on sperm nuclei. Sperm characteristics from a group of men of proven fertility were used as controls. Among the considered sperm characteristics, apoptosis (P < 0.01), 1818YY diploidy (P < 0.05) and 18YY disomy (P < 0.01) scores were significantly higher in men with RPL compared with controls. Our study showed that some patients with normal semen parameters can present a slight increase in aneuploidy compared with controls, indicating a possible involvement of sperm in some cases of RPL. Chromosomal FISH analysis and chromatin tests of sperm could be included in RPL work-ups when no other cause has been detected.