High fertilization rate with intracytoplasmic sperm injection in mosaic Klinefelter's syndrome.

With the introduction of intracytoplasmic sperm injection (ICSI) as a practical successful treatment for male infertility, we are able to offer the procedure to a group of patients who probably could never father a child of their own. From a patient with mosaic Klinefelter's syndrome, sufficient motile sperm for intracytoplasmic sperm injection were obtained from a fresh ejaculate estimated to contain < 100 motile sperm. In the first IVF-ICSI attempt, out of seven oocytes that were collected from the wife, four were mature and were injected by ICSI. Fertilization occurred in all four oocytes but only one cleaved and was transferred to the uterus. Pregnancy test was negative 16 days after ET. In the second treatment cycle four out of eight oocytes were selected for ICSI. All four fertilized, three cleaved at the right time, and two were transferred into the wife's uterus. One embryo was frozen. Pregnancy test 16 days after ET was negative. The high fertilization rate achieved in this case indicates the potential of ICSI to treat extreme male infertility. Its use offers hope to those patients with conditions previously considered to be untreatable.