Chromosomal abnormalities in couples undergoing intracytoplasmic sperm injection. A study of 370 couples and review of the literature.

Summary Intracytoplasmic sperm injection (ICSI) is now widely acknowledged as the most effective therapeutic approach to severe male infertility or unsuccessful in vitro fertilization. Cytogenetic investigations were performed in 370 females and 335 males prior to ICSI between January 1997 and April 2003. Nine men (2.7%) and 48 women (13%) had an abnormal karyotype, 44 females having some degree of numerical sex chromosome mosaicism. A review of the literature showed the prevalence of all types of chromosomal abnormalities to be much higher among male and female partners of couples examined prior to ICSI than among newborns. As most ICSIs are performed with ejaculated spermatozoa from oligospermic men, the distribution and the prevalence of the several types of chromosomal abnormalities are closer to those of oligospermic rather than azoospermic males. Our results combined with those of the literature stress the importance of karyotyping both male and female partners before ICSI is started. Adequate genetic counselling, possibly followed by prenatal diagnosis, should be offered if a chromosomal anomaly is detected.