Incidence of sperm chromosomal abnormalities in a risk population: relationship with sperm quality and ICSI outcome

An increased incidence of chromosome abnormalities has been reported in sperm samples of many infertile men by fluorescence in-situ hybridization (FISH).

Sperm aneuploidy and diploidy rates for chromosomes 13, 18, 21, X and Y were evaluated in 63 patients with normal karyotypes using dual and triple-colour FISH techniques. Indications for sperm FISH analysis were: recurrent miscarriages of unknown aetiology (RM, n = 40), repeated implantation failure after intracytoplasmic sperm injection (ICSI) (IF, n = 19), previous Down's syndrome pregnancies (n = 3), and meiotic abnormalities (MA, n = 1). Nine healthy normozoospermic donors were also evaluated as a control group.

A significant increase in the incidence of sex chromosome disomies was found in the RM, IF and MA groups. Oligoasthenoteratozoospermic patients (n = 21) showed significantly higher rates of diploidy and disomies for sex chromosomes and chromosomes 18 and 21 than normozoospermic patients (n = 14). Thirty-one patients with normal and seven with abnormal FISH results had undergone several ICSI treatments (108 and 23 cycles respectively). Couples with abnormal sperm FISH results showed decreased pregnancy and implantation rates and increased miscarriage rates.

Patients with a clinical background of recurrent miscarriages of unknown aetiology or implantation failure after ICSI are at risk of showing sperm chromosomal abnormalities, the incidence of which is higher in oligoasthenoteratozoospermic patients.