If you’ve had a semen analysis as part of infertility investigations, you’ve likely seen sperm morphology mentioned in your results. Here’s what you need to know about this measure of sperm health, what is normal when it comes to sperm morphology and whether abnormal results can affect your ability to conceive.
What is sperm morphology?
Sperm morphology is the physical appearance of sperm, and is assessed by examining size and shape. It’s one of several factors assessed when you do a semen analysis. Sperm with a smooth oval head and a long tail are the ones that seem best able to migrate through the female reproductive tract and reach the ovum (egg) to fertilise it, but most sperm have misshapen heads, crooked or extra tails, or no head or tail at all.
What is normal sperm morphology?
When you get a semen analysis, your sample will be looked at under a microscope by an embryologist to determine the number of sperm, their morphology and their movement. Your results will then be compared to the World Health Organization’s (WHO) reference values for fertile men. The WHO defines normal sperm morphology as more than 4% of sperm having morphology that is typical of those that seem best at fertilisation. That means it’s normal for the vast majority (96%) of sperm in a healthy sample to be abnormally shaped. The embryologist also notes exactly where the defects are on the sperm, because these could indicate what is causing the abnormal morphology.
What is teratozoospermia?
Teratozoospermia is when fewer than 4% of sperm have typical morphology. There’s no grading of teratozoospermia; just the 4% cut-off.
One of the measures from semen analysis is the teratozoospermia index (TZI), which is an average of the number of defects per abnormal sperm. There is a relationship between TZI and reproductive outcomes but it is not a useful predictor of fertility of pregnancy success.
What causes abnormal sperm morphology?
Common causes of abnormal sperm morphology include:
Does poor morphology mean you can’t conceive?
No, abnormal morphology doesn’t mean you can’t conceive. Sperm morphology alone is unlikely to have a significant impact on natural conception, intrauterine insemination (IUI) and in vitro fertilisation (IVF). It should be considered alongside other factors like sperm count and motility.
Even if the results of your semen analysis are within the normal range, it’s not a guarantee that you’re fertile. And you might still be able to conceive naturally if your results fall outside of the normal range. The results are more of a general guide to your likelihood of fertility.
Can sperm morphology be improved?
Many of the behaviours that are linked to abnormal sperm morphology can be changed — if you smoke you can quit, you can limit alcohol consumption and reduce chemical and heat exposure. When investigating male infertility, your doctor should do a physical examination to check for varicocele and symptoms of genetic conditions that could affect your sperm. You’re producing new sperm all the time and sperm development takes two to three months. So changes you make today will affect the sperm you produce three months from now.
Treatment options when morphology is affecting fertility
If natural conception isn’t happening, assisted reproductive technology can be used to overcome problems that might be caused by abnormal sperm. IUI can give the healthiest sperm direct access to the uterus and IVF with ICSI can put a single, healthy sperm directly into an egg.
People also ask
What supplements are good for sperm morphology?
There’s not much evidence to support the use of supplements for improving sperm morphology. If you’re concerned about your semen quality, the best way to maximise it is with a healthy diet, physical activity and avoidance of toxins like tobacco, alcohol and pollution.
Can poor morphology cause a miscarriage?
There is weak evidence for an association between abnormal sperm morphology and recurrent miscarriage.
Is 4% morphology bad?
No 4% sperm morphology is normal.
Can you conceive with 0 sperm morphology?
Yes.
