Sperm Morphology and Motility Comprise the 2 Ms of Male Fertility
If you're planning on starting a family, you should know there's much more to male fertility than just your ability to get and maintain an erection. Along with sperm count, the shape and movement of sperm cells have a significant impact on their ability to fertilize an egg. Here's a deep dive into how your swimmers may be impacting your fertility.
It takes only a single sperm cell to fertilize an egg and produce an embryo. However, multiple factors must line up for the process to work.
If you've been having unprotected sex for one year without a resulting pregnancy, there may be underlying fertility issues getting in the way. Both males and females can possess characteristics that contribute to infertility, and usually women should be tested as well to discover any potential abnormalities in their anatomy. To assess potential problems with sperm, your doctor can conduct a semen analysis, which involves collecting a sperm sample and sending it to a lab for evaluation of:
- Fluid volume: How much semen is in the sample?
- Morphology: How many of the sperm are shaped "normally"?
- Motility: What percentage of the sperm can move?
- Sperm count: How many sperm cells are in the sample?
The data gathered from a semen analysis can help determine whether natural conception is possible or you should consider assisted reproductive technology, such as in vitro fertilization (IVF). Sometimes, making healthy lifestyle changes or adjusting medications is enough to fix fertility issues. However, genetics, age and unavoidable environmental toxins may also be part of the problem.
Abnormally shaped sperm
The morphology, or shape, of a sperm determines its ability to penetrate the egg. It's not uncommon to have a percentage of sperm that are not perfectly shaped. In a typical semen sample, up to 50 percent of sperm may not be "normal-shaped," though ideally, 70 to 90 percent will have a normal shape.
Sperm abnormalities may include:
- Headless sperm: Also known as decapitated sperm or "pinheads."
- Macrocephalic heads: Large sperm heads that are irregularly shaped and usually have multiple tails attached (about 3.6 tails per head on average).
- Microcephalic heads: Sperm with small heads that are less than 3.5 micrometers long and 2.5 micrometers wide.
- Residual cytoplasmic material: Normal sperm cells contain a small amount of cytoplasmic residue around the midpiece, but in abnormal sperm, this area is 30 percent larger than the sperm head.
- Tail abnormalities: Abnormal sperm tails may be too thick, short, coiled or angular.
- Thin or elongated heads: Misshapen sperm heads that cannot penetrate the egg.
A rare type of male infertility is caused by a condition called globozoospermia, in which the sperm head is round instead of oval, and the acrosome (a cap that breaks down the egg cell membrane) is missing. Most of the time, globozoospermia is related to specific genetic mutations.
Along with genetics, sperm morphology issues may also be related to cannabis use, alcohol consumption, exposure to polychlorinated biphenyls (PBCs), high temperatures (such as a fever), testicular cancer and varicoceles (varicose-type veins in the scrotum). Working with a fertility specialist can help you identify and treat the underlying causes of abnormally shaped sperm.
Sperm motility issues
Sperm motility, or the number of actively moving sperm, should be between 60 and 80 percent in a healthy semen sample. Motility and morphology are closely linked as the function of sperm relies on their formation. Sperm motility also depends on metabolic pathways responsible for energy conversion.
Not all moving sperm can lead to conception. Some sperm may move too slowly or in an unproductive fashion, such as swimming in circles or twitching. More sophisticated sperm analysis techniques consider the percentage of high-velocity sperm that travel in a focused direction.
Many of the factors that contribute to sperm morphology concerns also relate to motility issues. An area of particular interest for sperm motility is the use of antioxidants. Oxidative stress is considered one of the common causes of poor motility. Some studies suggest that antioxidant supplements, such as vitamin C, selenium and coenzyme Q10, can improve male fertility. Talk to your doctor about the potential side effects of fertility medications and how the antioxidants found in nutritious foods can help improve your sperm motility.
Treatment options are available
Taking steps to improve your lifestyle through healthy eating, exercise and avoiding harmful substances can also boost fertility. Sometimes, however, these changes are not enough to overcome the underlying causes of male infertility and your doctor might call for genetic testing or other diagnostic methods, as well. If your semen analysis comes back with less-than-favorable results, you can consider several options to assist with reproduction. With the help of a qualified healthcare provider, you can explore ways to overcome morphology and motility problems.