There are many reasons why couples have trouble achieving pregnancy. A semen analysis is one of the tests your doctor will use to evaluate the number of sperm in your semen (your sperm count), whether they are normal (morphology), and how well they swim (motility).
A low sperm count may be caused by certain medications or a medical problem such as a blocked duct, low testosterone level, or a condition in which sperm back up into the bladder. Fever can also reduce sperm count. Some men may have enough sperm, but their sperm may not swim well enough to reach the egg. Also, sperm that are not normal in shape may not be able to penetrate and fertilize the egg. Your doctor can treat many of these problems.
Approximately 40 percent of infertility cases are caused by a male factor, and 20 percent of all infertility cases are caused by a combination of male and female factors. Infertility is defined as failure to achieve pregnancy after one year of unprotected intercourse.
Sperm are manufactured in the thread-like tubules that fill the two testes. These tubules, called seminiferous tubules, are lined with several layers of cells. Over a period of about three months, sperm cells in the layer closest to the tubule wall migrate to the tubule’s central passageway, called the lumen. These round, immature sperm cells gradually lengthen as they approach the lumen, developing the typical tadpole appearance of mature sperm. The head of the sperm contains the male genetic material, which will enter the egg and join the female genetic material during fertilization to form an embryo. The midpiece of the sperm provides the energy needed by the tail to propel the sperm forward. Results of treatment given to improve fertility may not be apparent for at least three months, the time from the beginning of sperm formation to the ejaculation of mature sperm. Outside the seminiferous tubules in the interstitium are the Leydig cells. These cells produce the male hormone testosterone, which is responsible for the development of such masculine physical characteristics as body and facial hair, large muscles and a deep voice. Testosterone also helps stimulate the sex drive and potency, or the ability to achieve and maintain an erection. Leydig cells almost always function well even if sperm production is poor.
Fertility depends on the man’s ability to deposit adequate numbers of healthy, mature, functioning sperm into the female reproductive tract near the time of ovulation. For most men, a detailed medical history, a complete physical examination and a semen analysis will be the major part of the fertility screening. Men who feel uncomfortable about the fertility evaluation should discuss these feelings with their partner and physician. Talking about anxiety beforehand can make the actual exam much easier. The physician will need information relevant to male fertility and will determine if adequate sexual contact is taking place. Sexual history may also be discussed at this time. Be prepared to answer questions about the following: general medical history; mumps after puberty; trauma to the testes; an undescended testis at birth; frequency of sexual intercourse; infection of the reproductive organs and bladder; a hernia in the groin; a vasectomy or vasectomy reversal; radiation or chemotherapy for cancer; if your mother took certain drugs like DES while pregnant; tobacco, drug and alcohol use; exposure to environmental toxins; thyroid disease; and sexually transmitted diseases.
After the medical history is completed, a physical examination is required. The physician generally concentrates on signs of testosterone production, genetic abnormalities, muscle and fat distribution, voice pitch, hair distribution and overall well-being. The testes and prostate are examined for consistency, size and evidence of abnormalities.
Your doctor will want you to provide a semen sample. The sample is collected by masturbation at your doctor’s office in a private, comfortable room. You will be asked to collect your semen in a sterile specimen cup. Another option is to collect your semen at home (during intercourse) in a special condom that you can get from your doctor. You must deliver your sample to the doctor’s office within 45-60 minutes after collecting it. Speak with your doctor about instructions for transporting the sample to the office. If the results are not normal or the sample is not complete because you missed the container for sperm collection, this test may need to be repeated. Test results often vary, so you may need to do this procedure more than once. A number of variables are checked in a semen analysis. The first of these is the sperm count, or the number of sperm per milliliter of semen. Normal semen usually contains at least 20 million sperm in each milliliter. The second variable is sperm motility, or movement of the sperm. In a normal specimen, usually more than half of the sperm are moving forward progressively. A sperm’s swimming motion helps it travel upward through the cervix to the uterus and fallopian tubes. Motility is also needed for the sperm to penetrate the egg’s tough outer shell-like covering for fertilization. The third variable is sperm morphology. Morphology is the medical term for shape or form. About half the sperm in normal semen have oval heads and slightly curving tails, which is normal. Every man has some abnormally shaped sperm. Most specialists believe that these abnormal sperm will not fertilize an egg. Many patients are concerned that abnormal sperm will increase the risk of birth defects, but this is not the case. A large percentage of abnormal sperm, however, may reduce the number of normal sperm with fertilizing potential. While evaluating sperm morphology, physicians also look for a large number of white blood cells, possibly indicating inflammation, infection or both. Other factors examined include semen viscosity (thickness) and semen volume (amount). Ejaculated as a liquid, semen immediately assumes a jelly-like consistency and then liquefies again within 30 to 40 minutes. Therefore, semen viscosity is examined at an interval after ejaculation when full liquefaction should have occurred. The volume of ejaculate varies normally from one to five milliliters; there are about five milliliters in a teaspoon. If the volume is low, the sperm may not reach the cervix.
Many functions of the sperm can be evaluated in the laboratory. The results of these tests are sometimes helpful to the physician in determining the likelihood of pregnancy or selecting treatments. The tests are not appropriate in every case and the patient’s physician will know best which tests to perform. These tests include fructose testing, postcoital testing, the antisperm antibody test, checking for white blood cells in semen, computer assisted semen analysis, sperm enhancement studies, sperm penetration assay, Acrosome Reaction tests, zona binding or hemizona assay, or the hypo-osmotic swelling test. The treatments of male infertility vary, just as the causes for it change from man to man. Treatment options include intrauterine insemination with sperm washing, donor insemination, micromanipulation of sperm (ICSI) used in conjunction with in-vitro fertilization, medicines or vitamin treatments, certain surgical procedures such as a testicular biopsy (TESE) or aspiration (TESA), or vasectomy reversal.
The study of infertility has come a long way over the last few decades. Gone are the days when physicians assumed that all infertility problems involved only women. A variety of factors can limit a man’s fertility: infection, hormonal imbalance, injury, varicoceles, even psychological and emotional problems. If a man is infertile due to a prior vasectomy, he has a good chance of regaining fertility after a vasectomy reversal. A couple faced with infertility should investigate all aspects of the problem with the guidance of a qualified physician. With the help of today’s advanced diagnostic and reproductive technologies, many infertile couples can achieve their goal of becoming parents.