Sperm chromosome analysis and outcome of IVF in patients with non-mosaic Klinefelter's syndrome

Objective: The aim of the study was to determine the potential risk for fetal chromosomal anomalies in non-mosaic Klinefelter's syndrome patients undergoing IVF and intracytoplasmic sperm injection. Design: Individually collected spermatozoa were isolated from wet testicular tissue preparations and fixed on glass slides using micromanipulation. Their nuclei were analyzed for chromosomes X, Y, and 18 by fluorescent in situ hybridization. Setting: Assisted reproductive technology program. Patient(s): Consenting patients with non-mosaic Klinefelter's syndrome undergoing testicular biopsy and IVF (fresh specimens) or following such treatment (cryopreserved specimens). Intervention(s): None. Main Outcome! Measure(s): The rates of numerical chromosome abnormalities for chromosomes X, Y, and 18 among spare testicular sperm and the pregnancy outcome following treatment. Result(s): Testicular sperm were found in 8 of 20 patients. Four couples became pregnant following embryo replacement. Sperm chromosomes were analyzed in five patients. One hundred and five sperm of 112 analyzed (93.7%) were normal with X to Y ratio of 50:55 (NS) respectively. Among the 112 sperm tested, seven (6.3%) demonstrated chromosomal abnormalities, of which five were related to the sex chromosomes and two to chromosome 18. One set of triplets, one set of twins, and two singletons (four males and three females) with normal karyotypes were born. Conclusion(s): Most of the testicular sperm retrieved from Klinefelter's syndrome patients demonstrates a normal pattern of sex chromosome segregation. Therefore, the risk of transmitting numerical sex chromosome abnormalities is relatively low and probably comparable with the rates found in other severe male factor infertility patient groups. (Fertil Steril(R) 2000;74:925-9. (C) 2000 by American Society for Reproductive Medicine.)