Male Fertility

What is Sperm Morphology in My Semen Analysis Results?

Sperm morphology, in the context of a semen analysis, refers to the size and shape of the sperm in a given semen sample. You want at least 4% of sperm to be a normal shape. Otherwise, you could have fertility problems because of abnormal sperm morphology.

Normal Sperm Morphology Range

A normal sperm has an oval head about 5-6 micrometers long and 2.5-3.5 micrometers wide, and a single long tail. When you receive results from your semen analysis, you will see a number that represents the percentage of sperm in the sample that have this normal size and shape.

There are different standards for what counts as normal, but a normal morphology range is between 4%-14%. You may see a different number for normal on a semen analysis depending on what system is being used. 4% is normal based on Kruger “strict” morphology, which has become the most common system for evaluating morphology. Since “normal” only requires that 4% of your sperm have a normal shape and size, you can tell that every male has abnormally shaped sperm.

Abnormal Sperm Morphology

Abnormal sperm morphology means that too many of the sperm in a sample have an abnormal shape – for example, they might have more than one tail or a crooked head.

This matters because having an abnormal shape might make it difficult for them to penetrate an egg. Abnormal sperm morphology may lead to male infertility.

It’s perfectly possible for an abnormally shaped sperm to fertilize an egg, and having abnormal sperm morphology does not necessarily mean you will be completely unable to fertilize an egg, but even when a man has a normal sperm count and normal sperm motility, some defects in sperm morphology may make it take longer to achieve pregnancy or even prevent it.

Ultimately, your doctor will look at sperm morphology together with count and motility, as well as any other tests you might take, to make an informed judgement about your fertility potential.

Morphology’s Impact on Treatment

Abnormal morphology may make some kinds of infertility treatments less effective. At least one study has shown that sperm morphology less than 4% can have a significant negative impact on fertilization rates for IVF.

Normally, when IVF is performed sperm and egg are combined in a lab dish and left to fertilize, hopefully forming an embryo. This part of the process can fail as a result of abnormal sperm morphology.

If you are planning to try in vitro fertilization and you know that sperm morphology is an issue, you may want to consider intracytoplasmic sperm injection, commonly called ICSI. In this procedure, eggs and sperm are harvested from the man and woman, and a single good-quality sperm is injected directly into an egg.

Get Treatment for Motility and Morphology Issues

Ultimately, male infertility problems are dynamic and you should see a male fertility specialist, typically an urologist or andrologist. Need a good recommendation for a doctor? Get in touch with us.

Haig Karsian

Contributor, Altora Health
Haig is interested in taking the latest research into health and fertility topics, and transforming it into educational content that is accessible for all. When he isn’t studying or writing for medical school, you can find him volunteering at his local ER.