treatment option. By the early 1990s, cutting-edge urologists were showing others how microsurgery could help them reverse vasectomies and remove obstructions. In a 1991 study, for instance, Arnold M. Belker, of the University of Louisville in Kentucky, demonstrated that such techniques produced semen in 86 percent of 1,247 men receiving first-time vasectomy reversals, with pregnancies in 52 percent of the couples.
While these techniques yielded improved results, other technologies already had proven their therapeutic worth. In 1980, South African urologist C. M. Weintraub showed that endoscopy could be useful in repairing ejaculatory ducts whose obstruction prevented semen from traveling to the urethra.
With in-vitro fertilization coming of age in the 1970s and 1980s, other urologists developed special assays to evaluate sperm for this high-tech procedure. They based their findings on techniques used by University of Hawaii School of Medicine's R. Yanagimachi, who suggested in 1976 that by injecting sperm into specially processed hamster eggs, he would be able to predict the sperm's function in vitro. Impaired sperm would not penetrate effectively.