Intracytoplasmic sperm injection in infertile patients with structural chromosome abnormalities

In the present study we investigated the results of cytogenetic analysis in male and female patients included in an intracytoplasmic sperm injection (ICSI) programme for severe male infertility as well as in conceptuses resulting from these ICSI treatments. In the 261 couples treated, 11 male (4.2%) and three female (1.2%) abnormal karyotypes were found, all consisting of structural chromosome anomalies. Chromosomal translocation exhibited the highest frequency (eight males and two females), and there were also three cases of chromosomal inversion (two males and one female) and one male with one additional marker chromosome. There was no difference in fertilization rates among couples with abnormal (n = 14) and normal (n = 147) cytogenetic results, and the rates of clinical pregnancy per ICSI attempt were 25.0% (5/20) and 20.6% (78/ 378) respectively. In pregnancies obtained in couples with normal karyotypes, all of the 108 fetuses were free of chromosomal abnormalities. Among the eight fetuses from couples with chromosome structural anomalies, three out of five and two out of three inherited from the cytogenetic defects found in their father or mother respectively. In this series of 83ICSI pregnancies there were no chromosomal abnormalities other than those inherited from the parents. These findings suggest that normal pregnancy rates can be obtained by ICSI in cases of chromosomal translocation in couples with severe male infertility. However, until further evaluations of available data can be performed, cytogenetic analysis must be conducted prior to ICSI in men with low sperm counts, and genetic counselling must include prenatal diagnosis for all growing conceptuses.