PURPOSE:This study was conducted to determine the frequency and contribution of chromosomal abnormalities in miscarriages and in couples with recurrent in vitro fertilization/intra cytoplasmic sperm injection (IVF/ICSI) failure.MATERIALS and METHODS:A total of 221 individuals; 79 with three or more recurrent spontaneous abortions and 142 with at least three IVF/ICSI failures. Chromosomal analysis from peripheral blood lymphocytes was performed according to standard cytogenetic methods using G-banding technique.RESULTS:Abnormal karyotype was found in 21 (9.50%) individuals. Of these 21 subjects, 4 (19.04%) exhibited sex chromosomal abnormalities and 17 (80.96%) had autosomal abnormalities. Male partners had significantly higher chromosomal abnormalities (5.88%) than of females (3.61%). These abnormalities were also higher in patients with recurrent spontaneous abortions than with IVF/ICSI failure (P < 0.05).CONCLUSIONS:These data may be indicative that chromosomal abnormalities are involved more in spontaneous abortions than in recurrent IVF/ICSI failure. Cytogenetic analysis could be valuable for these couples when clinical data fail to clarify the cause.