Oligozoospermia: Recent Progress in Andrology [antikvár]

Oligozoospermia: Recent Progress in Andrology. edited by G. Frajese et al. Raven Press. New York © 1981. Sperm Count and Fertility: Facts and Myths Rune Eliasson Reproductive Physiology Unit, Faculty of Medicine, Karolinska Institutet, S-104 01 Stockholm, Sweden Macomber and Sanders (10), in their 1929 report on semen analysis and fertility, noticed that pregnancies could occur with sperm counts below 60 million/ml, but that higher sperm counts were more likely to result in pregnancies. Contemporary authors claimed that pregnancies could not occur if the sperm count was less than 60 million/ml. During the 1950s and 1960s, MacLeod published a long series of semen analyses and concluded that sperm counts of 20 million/ml seemed to be the lower limit for normal fertility. The figure was later adjusted to 10 million/ml (9). Several publications during the 1970s have presented evidence that fertility seemed unimpaired even if the count was below 10 million/ml (3,5,13,14,16,17). However, despite these later reports, it is well known that most physicians working with human fertihty regard a man with sperm counts below 20 (or even below 40) million/ml as "infertile," or even "sterile." The belief that the higher the sperm count, the better the man's fertility, is indeed very deeply imbedded in the minds of many physicians. DEFINITION OF FERTILITY To be able to study scientifically the possible relationship between sperm count and fertility, we must introduce certain criteria. The first is related to the definition of fertility. In subhuman species, one can assess the fertility of a given male with fair accuracy from serial mating experiments or from the results of a high number of inseminations. For the human male, we are, on the other hand, almost always limited to an indirect evaluation. We can accept as fertile those men who provided semen for a successful AID, and we may accept those who are married to a woman pregnant in the first trimester and guaranteed by her as the father-to-be. We cannot, on the other hand, classify a man with children as a man of "proven fertility." He is a father, but from the scientific standpoint, his present fertility status is in no way clear from 1