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 in tubes called the epididymis. During erection, but before ejaculation occurs, the sperm travel from the epididymis to the vas deferens. During ejaculation, the sperm mixes with other fluids to form semen. Semen is pushed through the urethra and out of the body.

What Can Stand in the Way of Fertility?

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

• Varicocele —The development of a varicocele, or varicose veins in the scrotum, can sometimes affect sperm production. Removing the veins may boost fertility, though the evidence favoring surgery remains incomplete.
• 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.
• 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.
• 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 narrow the opening from the urethra to the bladder can alleviate this problem.

Maintaining Your Fertility

The average male produces 40-300 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, certain medications may stimulate testosterone production and sometimes boost sperm creation.

One way to maintain healthy fertility is 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 when the temperature is body temperature or higher. The placement of the testicles a few inches away from the body keeps them cooler than this.

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 njuries —Take care to protect your testicles while playing sports. If a sport requires a cup, it is a good idea to wear one. A cup will protect your testicles from injury if they get hit by an object.
• 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. However, pesticide residues in food have not been shown to affect fertility.
• Radiation —Men who are regularly exposed to radiation, which can occur with certain occupations or medical treatment, may experience fertility problems. If you have x-rays anywhere near your 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 treatment 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 for at least one year and are not having success, see your doctor.