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

BACKGROUND: An increased incidence of chromosome abnormalities has been rep orted in sperm samples of many infertile men by fluorescence in-situ hybrid ization (FISH). METHODS: Sperm aneuploidy and diploidy rates for chromosome s 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 an alysis were: recurrent miscarriages of unknown aetiology (RM, n = 40), repe ated implantation failure after intracytoplasmic sperm injection (ICSI) (IF , n = 19), previous Down's syndrome pregnancies (n = 3), and meiotic abnorm alities (MA, n = 1). Nine healthy normozoospermic donors were also evaluate d as a control group. RESULTS: A significant increase in the incidence of s ex chromosome disomies was found in the RM, IF and MA groups. Oligoasthenot eratozoospermic patients (n = 21) showed significantly higher rates of dipl oidy and disomies for sex chromosomes and chromosomes 18 and 21 than normoz oospermic patients (n = 14). Thirty-one patients with normal and seven with abnormal FISH results had undergone several ICSI treatments (108 and 23 cy cles respectively). Couples with abnormal sperm FISH results showed decreas ed pregnancy and implantation rates and increased miscarriage rates. CONCLU SIONS: Patients with a clinical background of recurrent miscarriages of unk nown aetiology or implantation failure after ICSI are at risk of showing sp erm chromosomal abnormalities, the incidence of which is higher in oligoast henoteratozoospermic patients.