When pregnancy does not occur after more than a year of unprotected intercourse in women under age 38 and within six months at older ages, a couple should see a fertility specialist. As a part of an initial infertility diagnostic workup, the fertility specialist often orders a semen analysis. Semen analysis tests quantity and quality of sperm. A complete semen analysis involves the assessment of many different parameters, but only three are really important:
At least 50% of sperm should "swim" in more or less straight line. Sperm that "moves" well is more likely to reach the egg.
At least 15% of the sperm should have a normal shape and structure, with an oval-shaped head. Abnormally shaped sperm is less likely to be able to fertilize an egg.
Sperm count should be above 20 million in a milliliter of sperm. Complete semen sample should have at least 40 million sperm.
When any one or more factors are "abnormal," male infertility may be diagnosed. Here is the real truth, however: Nobody really cares very much about what sperm counts, morphology and motility results really are. What we are really after is to find out how well sperm "functions." And sperm has only one biological function, which is to penetrate the wall of the egg (called zona pellucida), and to fertilize the egg. These factors are only approximations of that one crucial function of the sperm.
Unfortunately, we have no reliable test to determine how well sperm does in this function (as it would not be very ethical to test sperm against someone's eggs). We, therefore, do the next best thing: we test sperm function indirectly via a semen analysis. If sperm count, motility and morphology are all normal, then, with over 99 percent likelihood, the sperm's function will be normal as well, and if one or more parameters are abnormal, one can assume a fertilization problem exists. The severity of the fertilization problem is usually considered proportionate to the severity of observed abnormalities in the semen analysis.
Norbert Gleicher, MD, leads CHR’s clinical and research efforts as Medical Director and Chief Scientist. A world-renowned specialist in reproductive endocrinology, Dr. Gleicher has published hundreds of peer-reviewed papers and lectured globally while keeping an active clinical career focused on ovarian aging, immunological issues and other difficult cases of infertility.