The management of oligospermic infertility by in vitro fertilization

The fertilization rates of mature preovulatory oocytes aspirated from 156 women treated by in vitro fertilization were analyzed as a function of spermatozoal density and motility and the findings were correlated with the category of infertility (chronic oligospermia, tubal disease, endometriosis, serum antibodies to spermatozoa in the female, and unexplained infertility). Overall reduced fertilization rates were found in all cases if the semen sample presented on the day of fertilization demonstrated less than or equal to 5 million motile spermatozoa per milliliter, less than 40% motile forms, or the combined findings of less than 20 million per ml and less than or equal to 60% motile forms. Where the husband was known to have chronic oligospermia, reduced fertilization was found if the semen on the day of fertilization contained less than 20 million spermatozoa per ml and less than 12 million motile spermatozoa per milliliter. For cases of unexplained infertility, a poor fertilization rate was noted if the semen demonstrated less than 60% progressively motile forms regardless of the overall spermatozoal density, implying that a proportion of unexplained infertility is due to a disorder of spermatozoa reflected by reduced motility. Pregnancies were achieved in 5 of 26 cases with chronic oligospermia, including 2 where oligospermia was very pronounced (less than or equal to 5 million motile spermatozoa per milliliter).