What is sperm morphology?

If you were recently told by your doctor that you have abnormal sperm morphology, you probably have more questions than answers: What exactly does this mean? How does this affect my fertility? What can I do about it?

Morphology refers to the shape of your sperm, or what it looks like under a microscope. Specifically, it looks at the shape of the sperm head and the size of the sperm. The head shape is important because it affects the sperm’s ability to dissolve the outer surface of an egg and fertilize it.

Read on to learn more about sperm morphology and the impact it may have on your fertility.

What are sperm morphology ranges?

Sperm morphology ranges indicate what percent of sperm are considered normal in size and shape. These sperm are the most likely to be able to fertilize an egg, so the percentage can give you a clue about your chances for conceiving with your partner. The ranges will differ from lab to lab, depending on the criteria used to assess the sperm. Stricter criteria will result in a lower normal range.

Your doctor will discuss your range with you and help you determine what effect it has on your fertility. According to Dr. Jane Frederick, a leading board-certified reproductive endocrinologist in Orange County, “There are different ranges for morphology depending on the lab, but we use a strict Kruger morphology that means 14 percent or more is normal range. Ten to 14 percent is still good fertility potential, 5 to 10 percent is decreased fertility, and less than 5 percent is poor fertility potential.”

What is the relationship between sperm morphology and fertility?

Sperm morphology affects fertility because sperm have to be a certain shape to be able to penetrate an egg. But morphology is only one of many factors when it comes to fertility. Your doctor will also look at the number of overall sperm and how easily they move.

Does small-headed morphology mean IVF?

If your doctor tells you that you have small-headed sperm morphology, in vitro fertilization (IVF) may be an option. IVF is a procedure where your doctor extracts semen and injects it directly into eggs that have been removed from your partner. They then implant embryos that come from the process into your partner’s womb. This is an invasive procedure, but it can be an effective method for pregnancy. Talk with your doctor if you and your partner are ready to become pregnant.

Can you improve sperm morphology?

Your sperm is usually healthier the younger you are. Some physicians recommend freezing your sperm earlier in life so that you have your healthiest sperm available for use when you’re ready to start a family. If you’ve already learned that your sperm morphology range is low, it will be too late for that option, however.

Your body is always producing new sperm, so changes to your diet or lifestyle can impact the health of your future sperm, including:

  • losing weight
  • exercising regularly
  • avoiding heavy drinking, tobacco use, or illegal drugs
  • wearing loose cotton boxers

Some natural supplements and vitamins may be helpful for promoting normal sperm morphology too.

What are other possible causes of male fertility?

If you and your partner have been trying to conceive, and you’re concerned there may be an issue, see your doctor for a full workup. Sperm morphology is only one of many possible causes.

Medical conditions

There are many medical conditions that could make conceiving difficult. Conditions like varicoceles, infections, and hormonal imbalances can affect fertility. Even being diagnosed with celiac disease can be a factor.

Environmental concerns

Being exposed to chemicals or radiation at work or in your home can affect your sperm, and in turn your fertility.

Lifestyle choices

You probably know that smoking and illicit drugs aren’t a great idea when trying to conceive, but other lifestyle choices can also affect your fertility:

  • Limit alcohol consumption.
  • Maintain a healthy weight, or lose weight if you are overweight or obese.
  • Manage or reduce emotional stress.


Sperm morphology is only one small piece of the fertility puzzle, so it’s crucial to discuss your results with your doctor to see if your range could affect your chances of conceiving with your partner. Ask about any lifestyle changes you could start today, and take it from there.