Pregnancy obtained with human testicular spermatozoa in an in vitro fertilization program.

The fertilizing capacity of human testicular spermatozoa and the positive outcome of an in vitro fertilization program open a wide range of opportunities for men suffering from obstructive and inoperable azoospermia. In six cases, subzonal sperm injection or intracytoplasmic sperm injection techniques were applied to inject testicular spermatozoa into human oocytes. The fertilization rate after testicular sperm injection reached 45%. Normal cleavage was observed and replacement of 10 embryos in 6 patients resulted in one chemical and one ongoing pregnancy.