Nonsperm Cells These include epithelial cells, round cells, and isolated sperm heads or tails. Round cells include immature germ cells and leukocytes. Immature germ cell elevation suggests testicular damage, while leukocytes (predominantly neutrophils) are associated with inﬂammation. Leukocytes can be distinguished by peroxidase positive staining, and normal leukocyte concentrations should be less than 1 million/mL. However, the prognostic significance of leukocytes in the semen is controversial (30,50). When bacterial colonization is found, the most common pathogens are Chlamydia trachomatis (41.4%), Ureaplasma urealyticum (15.5%), and Mycoplasma hominis (10.3%) (51).
Antisperm Antibodies Antisperm antibodies, particularly those found on the surface of sperm, are associated with decreased pregnancy rates. Testing may be indicated with a history of ductal obstruction, prior genital infection, testicular trauma, and prior vasectomy reversal. It may be useful with oligozoospermia in the setting of normal hormonal levels, asthenospermia with normal sperm concentration, sperm agglutination, or unexplained infertility. Antisperm antibody testing is not needed if the sperm are to be used for intracytoplasmic sperm injection (ICSI) (44,47). Using the immunobead test, washed spermatozoa are exposed and assessed for binding to labeled beads. In the mixed agglutination reaction, human red blood cells sensitized with human immunoglobulin G (IgG) are mixed with the partner’s semen. Spermatozoa that are coated with antibodies form mixed agglutinates with the red blood cells (30).
Other Sperm Tests Although the standard semen analysis and associated tests provide a fairly reasonable picture of semen quality, they yield little information about sperm function. These specialized tests may be pursued to assess DNA integrity, fertilization potential (zona-free hamster oocyte test), and the effect of cervical mucus on sperm viability and function (postcoital test) (44,52). In general, these tests are not currently considered part of the standard assessment because their prognostic value and impact on management are limited by poor specificity, poor reproducibility, or controversies concerning the interpretation of the results (44,47,52).
If abnormalities in the semen are detected, further evaluation of the male partner by a urologist is indicated to diagnose the defect. Table 32.4 lists the differential diagnoses for male factor infertility (53). Several groups have attempted to assess the distribution of male infertility diagnoses; two such distributions are shown in Table 32.5 (54,55). The first is the result of a WHO study of 7,057 men with complete diagnoses based on the WHO standard investigation of the infertile couple (54). The figures include data from cases in which the male partner was normal and the presumed cause of the couple’s infertility was a female factor. The second distribution is the result of a study of 425 subfertile male patients (54). Although the two studies represent different populations (one is from a study of couples, the other from a urologic practice) and differ in their distribution of male infertility diagnoses, idiopathic male factor and varicocele predominate. Other anatomic and endocrine causes occur less frequently. Same sex female couples or single women without a male partner who desire pregnancy may be considered as part of this category.
Table 32.4 Etiologic Factors in Male Infertility
From De Kretser DM. Male infertility. Lancet 1997;349:787–790, with permission.
of autosomal dominant diseases such as achondroplasia and craniosynostotic conditions and somewhat higher rates of trisomy 21 (56). In mice, offspring of older fathers have decreased survival (57). Increased paternal age is associated with recurrent pregnancy loss (58).