Normally, one milliliter of semen should contain at least 15 million spermatozoa 1. With such an amount, we can talk about reproductivity - the ability to conceive. Among the 15 million cells, there are definitely mature and mobile ones. They'll reach the egg and make it grow into a baby. If the number is less than normal, then the diagnosis is "oligozoospermia." In this case, conceiving a child is possible, but they are decreasing. The lower the number of male germ cells, the lower the chance of fertilization.