Abstract: Objective：To investigate the effects of big and bit Y chromosome configurations on male fertility and to evaluate the relevant clinical significance.  Methods: The relevant cases were divided into A and B groups. Group A included male infertile cases. Group B included cases whose wives had adverse pregnancy history or the abnormal amniotic fluid punctures. The cytogenetics of the patients were examined by culturing peripheralblood lymphocytes and Gbanding technology, and karyotyping analysis techniques were used to study the big and bit Y chromosomes in the two different groups. Results: Among 2 139 cases, 98 cases were found with abnormal karyotype of big and bit Y chromosomes. There was no significant difference in the abnormal rate of the length variation of the Y chromosomal karyotypes between the male infertility group and the adverse pregnancy outcome group. In the male infertile group (group A), there was no significant difference in the abnormal rate between the big Y chromosome and the bit Y chromosome. In the group with adverse pregnancy outcomes (group B), the abnormal rate of the big Y chromosome karyotyping was significantly higher than that of the bit Y chromosome karyotyping. The main clinical effects of groups A and B were azoospermia, oligozoospermia, poor spermia, abortion, embryonic diapause and fetal anomalies, etc . Conclusion: The big and bit Y chromosomal abnormality results in not only the male infertility directly, but also an important and continuous reason of adverse pregnancy outcomes, of which the detailed mechanism needs to be further investigated.

Key words: Chromosome aberrations, Y chromosome, Infertility, male