Role of sperm fluorescent in situ hybridization studies in infertile patients: indications, study approach, and clinical relevance.

OBJECTIVE: To determine the group of infertile patients that would benefit from sperm fluorescent in situ hybridization (FISH) analysis, the number of chromosomes to be analyzed, and the diagnostic interpretation of the results obtained.

DESIGN: A retrospective study of sperm FISH analyses.

SETTING: Universitat Autònoma de Barcelona.

PATIENT(S): Three hundred nineteen infertile men.

INTERVENTION(S): Semen samples were processed for FISH.

MAIN OUTCOME MEASURE(S): The frequencies of chromosomal abnormalities for chromosomes 13, 18, 21, X, and Y were compared to the seminogram, the somatic and meiotic karyotype, and the age.

RESULT(S): The highest percentages of patients with an increased rate of sperm chromosome abnormalities were found in the oligozoospermic (50%), oligoasthenozoospermic (33.3%), and oligoasthenoteratozoospermic (21%) individuals. Low sperm count was the only parameter correlated with the percentage of chromosome abnormalities. The 14% of the individuals with a normal somatic karyotype had an increased rate of sperm chromosome abnormalities. This percentage was higher in the group with an altered somatic karyotype (36%) and in patients with meiotic abnormalities (26%).

CONCLUSION(S): Sperm FISH studies are indicated when the oligo condition is present and in individuals with an abnormal somatic or meiotic karyotype. The analysis of chromosomes 21, X, and Y is enough to identify at-risk individuals. Significant differences in the rates of chromosome abnormalities should be taken into consideration regardless of the numerical value.