Male Infertility Overview
Infertility is the inability to conceive after at least one year of unprotected intercourse. Since most people are able to conceive within this time, physicians recommend that couples unable to do so be assessed for fertility problems. In men, hormone disorders, illness, reproductive anatomy trauma and obstruction, and sexual dysfunction can temporarily or permanently affect sperm and prevent conception. Some disorders become more difficult to treat the longer they persist without treatment.
Spermatogenesis takes place in the ducts (seminiferous tubules) of the testes. Cell division produces mature sperm cells (spermatozoa) that contain one-half of a man's genetic code. Each spermatogenesis cycle consists of six stages and takes about 16 days to complete. Approximately five cycles, or 2 months, are needed to produce one mature sperm. Energy-generating organelles (mitochondria) inside each sperm power its tail (flagellum) so that it can swim to the female egg once inside the vagina. Sperm development is ultimately controlled by the endocrine (hormonal) system that comprises the hypothalamic-pituitary-gonadal axis. Because sperm development takes over 2 months, illness that was present during the first cycle may affect mature sperm, regardless of a man's health at the time of examination.
Incidence and Prevalence
According to the National Institutes of Health, male infertility is involved in approximately 40% of the 2.6 million infertile married couples in the United States. One-half of these men experience irreversible infertility and cannot father children, and a small number of these cases are caused by a treatable medical condition.
Causes and Risk Factors
The primary causes of male infertility are impaired sperm production, impaired sperm delivery, and testosterone deficiency (hypogonadism). Infertility can result from a condition that is present at birth (congenital) or that develops later (acquired). Causes of infertility include the following:
Defect or obstruction in the reproductive system such as failure of testes to descend into the scrotum (cryptorchidism) or absence of one or both testicles (anorchism)
Disease (e.g., cystic fibrosis, sickle cell anemia, sexually transmitted diseases [STDs])
Hormone dysfunction (testosterone deficiency; caused by a disorder in the hypothalamic-pituitary-gonadal axis)
Infection (e.g., prostatitis, epididymitis, orchitis; can cause irreversible infertility if they occur before puberty)
Injury (e.g., testicular trauma)
Medications to treat high blood pressure (hypertension) and digestive disease
Metabolic disorders such as hemochromatosis (affects how the body uses and stores iron)
Systemic disease (high fever, infection, kidney disease)
These procedures are performed to harvest sperm for in-vitro fertilization procedures to attain pregnancy. The MESA is a microscopic epididymal sperm aspiration, the TSA is a testicular sperm aspiration and the testis biopsy obtains testicular tissue to find individual sperm. The MESA and TSA or TESE use fine needles that are inserted into the various structures that sperm travel and aspirated. Very little seminal fluid is required since only one live sperm per cycle is required for intracytoplasmic sperm insertion (ICSI). These procedures are completed using a scrotal incision and can be completed in the office setting or in the hospital operating room.