Analyses of meiotic chromosomes in testicular biopsies of infertile patients.

Between 1989 and 1992 meiotic chromosome studies and synaptonemal complex analyses were evaluated using light and, in part, electron microscopy in 46 infertile males with highly abnormal spermiograms. This examination focused on whether the breakdown of spermatogenesis could be attributed to pairing anomalies of bivalents. The study of meiotic chromosomes and synaptonemal complexes indicated normal spermatogenesis in five patients (11%); in the remainder, maturation arrest was diagnosed. In 21 individuals (50%) the breakdown was accompanied by pairing anomalies (asynapsis, fragmented synaptonemal complexes, X/Y univalence). Thus it is shown that male infertility can often partly be explained by meiotic disorders.