Sperm Morphology vs. Motility: Which Matters More for Conception?

BySamradni Pradhan
Updated: 23 May 2025, 12:59 pm

When you're trying to conceive, reading a semen analysis report can feel confusing, especially when it comes to terms like sperm morphology and motility. Both play a key role in male fertility, but which one matters more? In this article, we break down the differences and explain which factor carries greater weight on your fertility journey.

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If you’re working your way through fertility issues, a semen analysis may be one of the first tests your doctor recommends. But once you receive the results, you may come across terms like morphology and motility, and it’s not always clear what they mean or how much they matter. While these factors are important, it’s worth noting that even men with poor morphology can still father children, and isolated poor morphology doesn’t necessarily indicate infertility. Let’s unpack both concepts so you can better understand your fertility and take informed steps forward.

In this article:



Understanding the Basics

Before comparing morphology and motility, it is important to learn what they are and why they matter for fertility.


What Is Sperm Morphology?

The shape and structure of sperm is referred to as sperm morphology. Microscopic examination of every sperm involves checking the head, midpiece, and tail. A "normal" sperm has:

  • An oval-shaped head
  • A well-defined acrosome (the cap that helps penetrate the egg)
  • A straight midpiece
  • A single tail that moves fluidly
If the shape is abnormal, such as a large head, double tails, or an irregular midpiece, the sperm may have a reduced ability to fertilise an egg.



What Is Sperm Motility?

Motility is the way sperm swim through your partner’s reproductive tract. For conception to happen naturally, the sperm has to swim up the cervix and into the uterus, then head toward the fallopian tubes so it can link up with the egg.

There are two key types of motility:

  • Progressive motility: Forward movement in a straight or large circular path.
  • Non-progressive motility: Movement without forward progression (e.g., twitching or swimming in place).

Sperm that can’t move efficiently, or at all, might not even reach the egg.


So, Which One Matters More for Conception?

Both morphology and motility are important, but motility tends to play a slightly more critical role in the actual fertilisation process.


Here’s why:

Motility Directly Affects the Journey to the Egg


Even if a sperm is perfectly shaped, it won’t matter much if it can’t move. Sperm need to travel a significant distance through the female reproductive tract. If they lack proper motility, they won’t make it far enough to reach the egg, let alone fertilise it.


Morphology Matters, But It’s Not Everything

While abnormal morphology can affect a sperm’s ability to penetrate the egg, some irregularly shaped sperm are still capable of successful fertilisation, especially with the help of assisted reproductive technologies (ART) like ICSI (Intracytoplasmic Sperm Injection).


In other words, poor motility can be a bigger obstacle to natural conception, while poor morphology might be more manageable, depending on severity and other factors.


How Are Morphology and Motility Measured?

You might be looking at your semen analysis results and wondering what all those numbers mean. Here’s a simplified breakdown of how each factor is assessed.


Sperm Motility


Motility is usually expressed as a percentage of moving sperm in your sample:

  • Normal: At least 40% total motility, with at least 32% progressive motility
  • Anything below this may indicate asthenozoospermia, or reduced sperm motility.

Sperm Morphology


Morphology is evaluated using criteria such as Kruger’s strict, stringent criteria. Typically:


  • Normal: 4% or more of sperm are normally shaped
  • Less than 4%: Considered teratozoospermia (abnormal morphology)
It might seem alarming if you’re told that only 4% of your sperm are “normal,” but that’s actually within the normal range by strict standards.


What Causes Abnormal Morphology or Low Motility?


Several lifestyle, medical, and environmental factors can affect morphology and motility.


Common Causes Include:


  • Lifestyle factors: Smoking, excessive alcohol, poor diet, lack of exercise
  • Heat exposure: Frequent hot baths, saunas, or tight underwear
  • Infections: STIs or chronic prostatitis
  • Hormonal imbalances: The variations in hormones
  • Varicocele: Enlarged veins in the scrotum
  • Oxidative stress: Damage caused by free radicals
  • Age: Sperm quality tends to decline as you get older

Improving Sperm Quality: What You Can Do

If your semen analysis reveals concerns with morphology or motility, don’t panic. There are proactive steps you can take, and in many cases, improvements can be seen within a few months, since sperm regenerate approximately every 72 days.


1. Prioritise Nutrition

A balanced diet of antioxidants (like vitamins C, E, zinc, and selenium) can support sperm health. Focus on whole foods: leafy greens, berries, nuts, lean protein, and whole grains.


2. Exercise Regularly

Physical activity, to an extent, can boost testosterone levels and enhance circulation, supporting healthy sperm production.


3. Reduce Heat Exposure

Exposure to high temperatures, such as hot tubs, laptops on laps, or tight-fitting underwear, can have a negative impact.


4. Quit Smoking and Limit Alcohol

Smoking and drinking are leading reasons for reduced motility and abnormal morphology. Cutting back or quitting can significantly improve outcomes.


When Should You Seek Fertility Help?


If you've been actively trying to conceive for 12 months (or 6 months if your partner is over 35) without success, it's a good time to consult a fertility specialist.

Based on your results, your doctor may recommend one of the following treatment options:

  • IUI (Intrauterine Insemination): This can be a helpful option if your sperm motility is slightly low but your overall sperm count is within a healthy range. It increases the chances of sperm reaching the egg by placing them directly into the uterus during ovulation.
  • IVF (in vitro fertilisation): If you have moderate to severe sperm abnormalities, IVF may be recommended. Eggs are fertilised outside the body in a lab setting, and the resulting embryo is transferred to the uterus.
  • ICSI (Intracytoplasmic Sperm Injection): This technique is particularly effective when sperm morphology or motility is significantly compromised. A healthy sperm is directly injected into an egg, bypassing many natural fertilisation barriers.

Sperm morphology and motility are critical for conception, but motility generally has a more immediate effect, especially when trying to conceive naturally. Even perfectly shaped sperm need to reach the egg to achieve fertilisation, which is why overall sperm health and motility are just as important as morphology.


Eventually, the most important thing is to understand your fertility profile. Together with a fertility specialist, with some targeted lifestyle changes and appropriate treatments, you can make significant strides toward better fertility and go forward with clarity and confidence.


FAQs On Sperm Morphology vs. Motility: Which Matters More for Conception?

  1. Can I still conceive naturally with poor sperm morphology?
    Yes, it’s possible. So long as a reasonable number of sperm are usually formed and other means, such as count and motility, are within range, natural conception is possible. Severely abnormal morphology, however, may lower the odds and may require assisted reproductive techniques.
  2. Is low sperm motility reversible?
    In many cases, yes. Some of the changes in the lifestyle, medical treatment of the infection or varicocele, and the use of antioxidants can increase the motility. Typically, improvement requires 2 – 3 months given the sperm production cycle.
  3. What’s more important in IVF: morphology or motility?
    In IVF, particularly in the case of its usage with ICSI, a single healthy sperm can be selected and injected right into the egg. In such circumstances, morphology and motility are less important than natural conception.
Disclaimer: Medically approved by Dr Sandhya Rani, Sr. Consultant - Obstetrics & Gynaecology, Aster Women & Children Hospital, Bengaluru