Oligospermic infertility treated by in-vitro fertilization.

A series of 451 couples receiving treatment in an IVF programme were classified according to the quality of semen produced by the male partner, and were regarded as either severely oligospermic (less than or equal to 5 X 10(6) motile spermatozoa/ml X n = 29), moderately oligospermic (5.1 to 11.9 X 10(6) motile spermatozoa/ml; n = 46) or normospermic (greater than or equal to 12 X 10(6) motile spermatozoa/ml; n = 376). Despite similar insemination numbers, a significant reduction in the proportion of oocytes fertilized was seen when the normospermic group (1,314/1,815; 72%) was compared with the moderately oligospermic group (134/239; 56%) and the severely oligospermic group (57/190; 30%) and there was a progressive increase in the proportion of couples with total fertilization failure in the 3 groups (18/376, 5%; 10/46, 22%; 12/29, 41%) respectively. In addition, 10 couples with severe oligospermia chose to divide the oocytes collected for insemination by the husband and a donor. The fertilization rates achieved using the husband's spermatozoa (9/31; 23%) are significantly lower than with donor (26/35; 74%), despite similar insemination densities, suggesting a functional defect in the spermatozoa of oligospermic husbands. Nonetheless, the pregnancy rates following embryo transfer were similar for all groups, suggesting that once fertilization is achieved, all embryos have the same potential to result in a successful pregnancy.