Male Biology

The importance of sperm.

For men, an essential part of fertility involves the creation of normal, mature sperm.

The process works like this. Sperm is created in a man's testes and passes through the epididymis which stores and nourishes the sperm. Once this occurs, the sperm travels through the vas deferens and is stored in the seminal vesicles.

When a man ejaculates, the sperm mixes with fluid to create semen. If the sperm are healthy and able to travel through a woman's cervix and uterus and into her fallopian tubes, it may fertilize the egg.

A man will continue to produce sperm, no matter what his age. However, age can negatively impact male fertility. Find out more about how age affects fertility.

The critical role that hormones play.

A man's reproductive system is dependent upon hormones that stimulate and regulate the production of his sperm. You may be surprised to learn that many of the same hormones that control a woman's reproductive cycle also control a man's reproductive system:

• Follicle stimulating hormone (FSH) stimulates sperm production.
• Luteinizing hormone (LH) stimulates the production of testosterone.

Finding that delicate balance.

Creating sperm is a complicated process. The body must generate hormones at the right time, in the proper amounts, in order for healthy sperm production to occur. Any disruption in this process can make it difficult to conceive. In addition, age and certain lifestyle choices may also impact sperm production. For example, smoking and excessive use of alcohol have been shown to have a negative effect on a man's fertility.

And by the way...

The male partner is just as likely to be the source of infertility as the female partner. The cause is attributable to male factors approximately a third of the time, to female factors a third of the time, and for the remainder, infertility is caused by a combination of problems in both partners, or is unexplained.[1]

If you're concerned about infertility issues, you may wish to see a healthcare provider.

For more information about male biology and fertility, read the booklet "Infertility: The Male Factor" (606 KB).