[Chromosome polymorphisms and their influence on semen quality and sperm DNA integrity in males undergoing IVF/ICSI]

To investigate the incidence of chromosome polymorphisms and their influence on semen quality and sperm DNA integrity in male patients receiving in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI).

We retrospectively analyzed the chromosomal karyotypes and the types and incidence rate of chromosome polymorphisms in 2 370 male patients undergoing IVF/ICSI between June 2016 and June 2018. We classified the patients into groups A (with variation in the secondary constriction region in the autosomal long arm), B (with variation in the short arm of the D/G group chromosomes), C (with interbrachial inversion of chromosome 9) and D (with Y chromosome polymorphisms), and compared the semen parameters and sperm DNA fragmentation indexes (DFI) between the patients with chromosome polymorphisms and those with normal chromosomes.

Totally, 154 (6.50%) of the patients undergoing IVF/ICSI were found with chromosome polymorphisms, including 34 cases of secondary constriction variation in the long arm of the autosome (1.43% ［34/2 370］, 22.08% ［34/154］), 82 cases of short arm polymorphisms of the D/G group chromosomes (3.46% ［82/2 370］, 53.25% ［82/154］), 26 cases of interbrachial inversion of chromosome 9 (1.10% ［26/2 370］, 16.88% ［26/154］), 10 cases of Y chromosome polymorphisms (0.42% ［10/2 370］, 6.50% ［10/154］), and 2 cases of mixed chromosome polymorphisms (0.08% ［2/2 370］, 1.42% ［2/154］). The total sperm count was lower in group D than in the other polymorphism groups and the normal chromosome group, but with no statistically significant difference among the five groups (P > 0.05). The sperm progressive motility was also lower in group D than in the other five groups, with statistically significant difference from group B (27.5 ± 13.5 vs. 41.5 ± 21.1, P = 0.027), but not from the other groups (P > 0.05). No statistically significant difference was observed in the sperm DFI between the polymorphism groups and the normal chromosome group (P > 0.05), or among the polymorphism groups (P > 0.05). The proportion of normal semen was lower in group D than in the other four groups, but with no statistically significant difference among the five groups (P > 0.05). The incidence rate of asthenospermia was higher in group D than in the other four groups, but with no statistically significant difference among the five groups (P > 0.05), and so was that of oligoasthenospermia, with statistically significant difference from the normal chromosome group (30.0% vs 8.0%, P = 0.041), but not from the other polymorphism groups (P > 0.05).

Short arm polymorphisms of the D/G group chromosomes are the most common type of chromosome polymorphisms in male patients undergoing IVF/ICSI. Polymorphisms of the Y chromosome have a negative effect on semen quality, while those of the other chromosomes do not significantly affect semen quality and sperm DNA integrity.