Male Infertility is a Factor 45% of the Time The male factor has been shown to be the underlying cause of infertility in 45% of couples who have difficulty getting pregnant. When you know the whole story of sperm, it becomes fairly easy to spot the ways that the male factor can become an issue. Unlike a woman who is born with all the eggs she will ever have, a man must constantly produce new sperm. In a healthy male, sperm are produced continually at a rate of roughly 100 million sperm per day and each sperm takes about 42 to 76 days of temps 2 degrees cooler than the body (hence the testicles hanging outside) to mature into a streamlined profile of sperm cells. Sperm production numbers are big because they have to be - a single ejaculation may contain up to 150 million sperm but only roughly 15% of those will be perfectly normal sperm that can penetrate an egg. Male fertility is, in part, a numbers game - the more sperm, the better the chances.
But there is more to the sperm story. Motility and morphology are also key factors besides count - that is, sperm have to swim straight and fast and be of the right shape in order to reach and penetrate the egg. From the time the sperm is ejaculated to when the egg is fertilized, sperm will first have to swim through the cervical mucus and cervix, and then swim up the fallopian tubes. Considering that the size of a sperm is roughly 0.002 inches long (not visible by the naked eye), this would be about the same as going from Hawaii to L.A. (or at least it feels that way to the sperm!). The fastest of the sperm will take about 45 minutes and the slowest need around 12 hours to reach the egg. Most sperm never make it. They either run out of energy, go in the wrong direction, or chase their tails in circles. Some sperm have been killed off by natural antibodies or hostile cervical fluids. In the end, it's just a few, fine-figured sperm that find their way to the egg and hope to become the lucky one.
