You may not choose to become a father at aged 77, but from a strictly biological perspective, it is within the realm of possibility. Most men produce sperm for their entire lives.

The male reproductive system is relatively simple; as a result, it generally functions quite efficiently. Sperm are produced in the testicles and stored within the scrotum in a "sack" called the epididymis. During erection, but before ejaculation occurs, the sperm travel from the epididymis to the vas deferens. The vas deferens is the tube that is severed in a vasectomy. The sperm is then propelled to the urethra where they mix with other fluids to form semen, which is ejaculated through the tip of the penis.

What Can Stand in the Way of Fertility?

Certain medical conditions can interfere with the proper functioning of the reproductive process. They include:

• Lack of Physical Structures or Blockages—Some men are born without a vas deferens or with tubal blockages. These conditions may be treated with surgery.
• Varicocele—The development of a varicocele, or varicose veins in the scrotum, which occurs in nearly 20% of men, can sometimes affect sperm production. Removing the veins may boost fertility, though the evidence favoring surgery remains incomplete.
• Retrograde Ejaculation—A condition in which semen travels in the wrong direction back into the bladder rather than being released through the penis. This can be caused by prostate and other types of surgery in the pelvic area. Drugs that close the opening from the urethra to the bladder can alleviate this problem.
• Diabetes and Multiple Sclerosis—These conditions can impair the nerves that promote normal ejaculation.
• Infections—Urinary tract, prostate, or tubal infections can cause blockages that can be treated by antibiotics. Gonorrhea and chlamydia are sexually transmitted infections that can scar the epididymis; however, these scars can be treated with microsurgery.

Maintaining Your Fertility

The average male produces 60-100 million sperm per milliliter (mL) of semen. Low sperm counts are not considered a problem until they get as low as 20 million per mL, which is diagnosed as oligospermia. That may still sound like an enormous number, but statistics show that it is more difficult for couples to conceive at this level.

Conception is difficult at low sperm levels, because even at full count, only a fraction of sperm survive the difficult journey from the vagina through the uterus to the fallopian tubes, where conception takes place. The sperm must be strong swimmers. A man can have a low sperm count but still successfully conceive if his sperm have good motility.

Semen analysis can tell you the quantity and quality of your sperm. If your sperm count is critically low, a drug called clomiphene citrate, which stimulates testosterone production, can sometimes boost sperm creation.

One way to maintain healthy fertilityis to adopt a fertility-friendly lifestyle.This can be done by avoiding smoking and alcohol. You can also increase your physical activity, eat right, and maintain a healthy weight.

The temperature of the testicles is one of the most significant factors in fertility. Testicles do not produce sperm well at high temperatures. That is why nature, in its infinite wisdom, placed the testicles a few inches from the body. This keeps them cool. Men with undescended testicles have difficulties producing sperm.

Men who wear tight pants and/or tight briefs, regularly use saunas, jacuzzis, hot tubs,or whirlpools or even take frequent hot baths might have lower sperm counts. When you stop these activities or change to looser clothing, it may increase your sperm count.

Other factors that can adversely affect fertility include:

• Sports Injuries—Take care to protect your testicles while playing sports. If a sport requires a cup, it is a good idea to wear one. It is not unheard of for men to be hit in the testicles with a golf ball or a tennis ball, therefore, it makes good sense to wear a cup whenever you participate in physical activity.
• Exposure to Chemicals—Herbicides and pesticides can affect fertility. If you use them in your garden, be sure to follow instructions carefully and take appropriate precautions. Pesticide residues in food, however, have not been shown to affect fertility.
• Radiation—Men who are regularly exposed to radiation such as lab technicians may experience fertility problems. If you have x-rays anywhere near the testicles, be sure to have the technician shield your groin area with a lead blanket. The radiation from computer or television screens has not been found to be a problem.
• Smoking—A review of the literature indicates that cigarette smoking is associated with modest reductions in semen quality including number of sperm and motility.
• Obesity—Obesity has been cited as a risk factor for male infertility in studies that looked at couples attempting to conceive.
• Prescription Medications—Various drugs have been found to affect the number or appearance of sperm in animals and occasionally in humans:
  • Sulfasalazine—for the treament of ulcerative colitis
  • Cimetidine—for the treatment of peptic ulcer
  • Monoamine oxidase inhibitors—for the treatment of depression
  • Chemotherapy drugs—for the treatment of cancer

If you and your partner have been trying to conceive and are not having success, see your doctor.