Hormonal evaluation in male infertility
Recent progress in the study of the hormonal regulation of spermatogenesis justifies endocrine examination in the case of male sterility. The most important complementary investigation are the assays of FSH, LH and plasmatic testosterone. Radioimmunoassay of FSH is the fundamental examination, since this hormone is considered to be an indicator of germinal function. Thus, in the case of oligospermia, or even azoospermia, FSH assay is decisive. When the FSH levels (in conjunction with LH levels) are high and combined with azoospermia, there is a possibility of testicular dysgenesis linked with a karyotype anomaly (XXY etc.). In some cases the germinal affection is secondary to cryptorchidism, orchitis, torsion, medicinal alteration, or radiotherapy. Decreased testosterone values combined with an insufficient FSH and LH response to stimulation tests indicate a gonadotrophic deficit, which is the best indication for substitution therapy using gonadotrophins or LH-RH. An increase in LH, contrasting with a normal FSH value, evokes the exceptional case of a disturbance of androgen receptivity. Normal FSH (and LH) values suggest excretory sterility. Lastly, when hyperprolactinemia is suspected, an assay of plasmatic prolactin is necessary. A “simple” hormonal evaluation allows a routine etiological approach to the diagnosis of sterility, and is thus an important element in the investigative strategy applied to male sterility, used along with the other complementary and indispensible examinations.
Hormonal evaluation of female infertility and reproductive disorders
Performance of the male and female reproductive systems reflects the orderly operation of the hypothalamic-pituitary-gonadal axis. Aberrant operation of this axis can result in many different reproductive disorders, including various forms of infertility. Proper evaluation of these disorders involves a multifaceted diagnostic approach, which includes a critical contribution from the clinical laboratory. This adjunctive testing, involving the measurements of peptide and sex-steroid hormone concentrations, allows the clinician to biochemically “dissect” the hypothalamic-pituitary-gonadal axis and ascertain the presence as well as location of the specific defect. In practice, the specific tests utilized during the evaluation of a patient depend upon the underlying disorder. Typically, in evaluating the reproductive disorders discussed in this review, a primary battery of tests is obtained that reflects the initial clinical presentation and physical examination. The results of these initial studies then dictate any secondary testing required to complete the evaluation. Such an approach, in use at our institution, is provided in Table 5. Although this discussion has concentrated on the laboratory assessment of the female reproductive system, it is important to remember the special case of infertility, where couples, in general, are evaluated together by the clinician. The cause of infertility can reside with the female, the male, or, in the cases of immunological “incompatibilities,” a combination of the male and the female. As such, rigorous schemes for evaluating male reproductive disorders (1, 3, 89-94) and immunological incompatibilities (95-98) have been developed, and the information derived from such testing represents a critical contribution to establishing the etiology of a couple’s infertility. Although the laboratory assessment of peptide and sex-steroid hormone concentrations clearly plays a pivotal role in the evaluation of reproductive disorders, these diagnostic tools probably will continue to change and improve in the years to come. Such changes will probably occur as the finer details of the operation of the hypothalamic-pituitary-gonadal axis become known. With this improved knowledge, we should have the capacity to design assays that will allow more clinically refined and biochemically precise means of diagnosing and treating specific reproductive disorders.
