Approximately 15% of couples attempting their first pregnancy meet with failure. Most authorities define primary infertility if the couple has been unable to achieve a pregnancy after one year of unprotected intercourse. Conception normally is achieved within twelve months in 80-85% of couples who use no contraceptive measures, and persons presenting after this time should therefore be regarded as possibly infertile and should be evaluated.
Data available over the past twenty years reveal that in approximately 30% of cases pathology is found in the man alone, and in another 20% both the man and woman are abnormal. Therefore, the male factor is at least partly responsible in about 50% of infertile couples.
Important issues related to the evaluation of the male factor include the most appropriate time for the male evaluation, the most efficient format for a comprehensive male exam, and definition of rationale and effective medical and surgical regimens in the treatment of these disorders.
It is extremely important in the evaluation of infertility to consider the couple as a unit in evaluation and treatment and to proceed in a parallel investigative manner until a problem is uncovered. It has been shown that the longer a couple remains subfertile, the worse their chance for an effective cure. Many couples experience significant apprehension and anxiety after only a few months of failure to conceive. Unduly prolonged unprotected intercourse should not be advocated before a workup of the man is instituted. Initial screening of the man should be considered whenever the patient presents with the chief complaint of infertility. This initial evaluation should be rapid, non-invasive and cost effective.
Of interest is the fact that pregnancy rates of up to 50% have been reported when only the woman has been investigated and treated even when the man was found to have moderately severe abnormalities of semen quality.
Fertilization normally takes place within the uterine tubes after ovulation has occurred. During the menstrual mid cycle, the cervical mucus changes to become more abundant, thinner and more watery. These changes serve to facilitate entry of the sperm into the uterus and to protect the sperm from the highly acidic vaginal secretions. Physiologic changes in the spermatozoa known as capacitation occur within the female reproductive tract in order for fertilization to occur. As the sperm cell interacts with the egg, there is initiation of new flagellar movement called hyperactive motility and morphologic changes in the sperm that result in the release of lytic enzymes and exposure of parts of the sperm's structure known as the acrosome reaction. As a result of these changes, the fertilizing sperm cell is able to reach the oocyte, traverse its various layers, and become incorporated into the ooplasm of the egg.
Semen analysis is one of the investigations that could reflect the inability of fertilization:
Nomenclature for Semen Variables
These are parameters as set by the WHO Laboratory Manual for the examination of human and sperm-cervical mucus interaction (4th edition).
Normal semen parameters:
- Count: > 20 million/ml
- Motility: >50% (WHO)
- Morphology: >15% normal (WHO)
- Volume: >2ml (WHO)
- pH: 7.2-7.8 (WHO)
- Normozoospermia: normal ejaculate as defined by the reference manual.
- Oligozoospermia: sperm concentration less than reference values.
- Asthenozoospermia: less than the reference value for motility.
- Teratozoospermia: less than the reference value for morphology.
- Oligoasthenoteratozoospermia: signifies disturbance of all three variables (combinations of only two prefixes may also be used).
- Azoospermia: no spermatozoa in the ejaculate.
- Aspermia: no ejaculate