It’s something that many of us will take for granted: have sex, get pregnant. However, it’s not always so straightforward. Infertility is a growing problem worldwide, affecting 1 out of every 8 couples. It’s estimated that about 1 in every 3 cases is due to the male partner alone. Although infertility can be due to a variety of conditions, sperm quality is usually a good predictor of fertility.

Sperm motility

Motility refers to the ability of the sperm to move or “swim,” which is essential for them to move through the female reproductive system and fertilize the egg. Progressive motility is the best type of movement that can be seen in sperm testing—that means the sperm move forward in straight lines or in large circles, as opposed to in small tight circles or along erratic paths.

Sperm morphology

Morphology means the sperm’s structure or shape, which is ideally:

• the tail, made of protein fibers, which helps it “swim” toward the egg
• the midpiece, or body, which contains mitochondria to power the sperm’s movement
• the head, which houses the nucleus where the sperm’s precious cargo—genetic information—is stored, as well as the acrosomal vesicle, a tiny structure at the tip of the sperm full of enzymes that helps the sperm penetrate the egg by digesting proteins and sugars on the surface of the egg.

This shape is important because it impacts a sperm’s ability to travel to and penetrate and fertilize an egg.

So, as you might imagine, the integrity of genetic material in sperm is essential for successful fertilization and normal embryo development. Sometimes, that DNA can become damaged, broken, or otherwise abnormal, known as sperm DNA fragmentation. DNA fragmentation directly correlates to lower fertility in men, and is also linked to recurrent pregnancy loss (two or more consecutive miscarriages).

DNA fragmentation can be caused by many factors, including age, fever/illness, smoking, and exposure to toxins. Learn more in our guide to DNA fragmentation.

The other half of the sperm equation is sperm quantity, or sperm count/concentration. Sperm count is the total number of sperm in a particular quantity of semen, the fluid that carries sperm out of the penis. Sperm concentration refers to how densely packed those sperm are within the semen. For example, a sample may include 3 milliliters of semen and a total sperm count of 45 million; that would be a concentration of 15 million sperm per mL.

Sperm quantity and sperm quality are separate factors; a high sperm count isn’t entirely helpful to fertility if most of those sperm are misshapen, can’t swim properly, or carry damaged DNA. But sperm quality issues and low sperm count can be caused by some of the same things, including exposure to toxins or chemotherapy, smoking, and hormone imbalance.

Age

As a man ages, his sperm motility decreases (according to one study, on average about .8% per year). Additionally, he has lower numbers of sperm with normal morphology—research indicates that normal sperm morphology declines .2–.9% per year, resulting in a 4–18% decrease in normal morphology over a 20-year period. And finally, the sperm of older men is more likely to have higher rates of DNA fragmentation, as well as additional genetic mutations that can lead to schizophrenia, autism, and more. The best way to prevent the issues associated with aging sperm is to freeze your sperm at a younger age. Learn more about sperm freezing.

The test can be done in a fertility clinic or urologist’s office, or can be done from the comfort and privacy of home with a mail-in sperm testing kit, like we offer. The results of your semen analysis will tell you which of your sperm parameters are normal, and which (if any) are abnormal. The Legacy semen analysis report also includes personalized recommendations to improve sperm quality, based on your lifestyle.