The most accurate recent surveys indicate that 8.6 million couples in the United States would like to have children but cannot. They are said to be involuntarily infertile. In 40 to 50 percent of the cases, a "male factor" is considered to be wholly or partially responsible for the couple's sterility. The term "male factor" is appropriately vague, for it encompasses a range of problems from abnormal sperm development to lack of the spontaneous sperm-ovum fusion required for fertilization to occur.
To understand why problems might occur, it is necessary to review the reproductive process so that you and your partner understand the details of what makes it possible for men and women to have babies. Then we can outline the whole range of treatments now available for infertile couples to first identify and then correct their own problem and start a family.
During ovulation, a woman releases one egg (ovum), which then drifts into her fallopian tube. It is there in the fallopian tube that a single sperm will penetrate that ovum to achieve fertilization.
A man's fertility depends upon his ability to generate not just one but millions of sperm daily. Although only one sperm is needed for fertilization, the odds against this single sperm meeting up with that one ovum are formidable. To improve chances for natural conception, the system is flooded with sperm. During sexual intercourse, several million sperm are deposited in the vagina. Many perish immediately in the hostile acid environment of vaginal fluids. Others die at the cervix, the entrance to the womb.
Freshly ejaculated sperm can swim, but they cannot fertilize. They are buffeted by a sea of fertility-impeding chemicals called decapacitating agents. To acquire full fertilizing capability, sperm must be transformed, or capacitated. Normally this occurs as sperm pass through the uterine cervix.