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As with women, hormones are essential to reproductive health in all aspects of a man’s sexual life. An area of the brain called the hypothalamus and the pituitary gland, located at the base of the brain, work together to release hormones— luteinizing hormone (LH) and follicle stimulating hormone (FSH) —that stimulate the testes to produce testosterone and sperm. Testosterone is responsible for the typical male characteristics and helps maintain sex drive; sperm production; facial, pubic, and body hair; muscle; and bone.
In men, important health issues related to hormonal imbalances or deficiencies include:
- Male Hypogonadism—lower than normal levels of testosterone (the main male sex hormone)
- Male Infertility—inability to produce sperm adequate for reproduction
- Sexual dysfunction
These conditions are often, but not always, related to each other.
Male Infertility
Infertility is the inability of a sexually active couple, not using birth control, to get pregnant after one year of trying. Infertility affects more than three million couples in the United States. Male problems play a role in 30 to 50 percent of infertile couples. Diagnosis of male infertility begins with a review of the patient’s medications, a physical exam, and analysis of several semen samples. Problems with low sperm count (not producing enough sperm) or poor sperm quality (sperm that do not move well or are misshapen) are common factors in male infertility. Measurements of testosterone, luteinizing hormone (LH), and follicle stimulating hormone (FSH) are also needed to determine the specific cause of the man’s infertility.
Reasons for male infertility
Many different conditions and physical problems can lead to infertility. In about 30 to 40 percent of cases, the problem is in the testes, the glands that produce sperm and testosterone. Damage to the testes can result from mumps, radiation or chemotherapy, trauma, or surgery. Many men have a varicocele, a collection of varicose veins in the scrotum. Blood flows in an abnormal direction in these veins, towards the testes. A varicocele raises the temperature in the testes, which can cause low sperm production. Certain inherited (genetic) diseases, such as cystic fibrosis and Klinefelter syndrome, can cause low or no sperm production.
In about 10 to 20 percent of cases, the problem is a blockage in the sperm’s path from the testes, through tubes called the vas deferens, to the penis. Backward movement of sperm into the bladder instead of out through the penis can also cause infertility. Anything that lowers LH and FSH levels, such as a pituitary tumor, can result in low or no sperm production and low testosterone levels (see the section on Causes of male hypogonadism).
In 30 to 40 percent of cases, the cause of infertility can’t be identified but these men usually have abnormal sperm (sperm that are slow moving, deformed, or few in number). Chronic illness, poor overall health, obesity, and drug abuse may also decrease sperm production and fertility.
Treatment of male infertility
Treatment for male infertility depends on the cause. Surgery can repair a blockage in the sperm transport system. A varicocele can also be repaired surgically, but surgery may not restore fertility. Such repair is more likely to bring back fertility if the veins are large or if the repair is done before any long-term damage.
If the cause is too little LH and FSH stimulating the testes, caused by a pituitary or hypothalamic disorder, treatment with LH and FSH hormone injections is usually successful. However, it may take a year or longer of hormone therapy to get enough sperm production and bring back fertility. Men with low to zero sperm counts caused by a testicular disorder do not respond to hormone injections.
Other options for a couple to get pregnant include assisted reproductive technologies such as inserting collected sperm into the womb (known as intrauterine insemination or IUI), mixing sperm with an egg outside the body (known as in vitro fertilization, IVF), or injecting a single sperm into an egg (known as intracytoplasmic sperm injection, ICSI).
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