Low Sperm Motility: Causes, Testing, and Treatment Options

A semen analysis can provide important insight into male fertility. While many people focus on sperm count, the test also looks at how sperm move. Sperm motility — or how well sperm swim — is essential for natural conception because sperm must travel through the reproductive tract to reach the egg. When sperm movement is limited, it can hinder its ability to complete the journey and fertilize the egg.

What Is Low Sperm Motility?

Low sperm motility, also called asthenozoospermia, occurs when sperm have difficulty moving efficiently. For natural conception to occur, sperm must swim through the cervix, uterus, and fallopian tubes to reach the egg. This requires strong forward movement. Some sperm, however, may move slowly or drift in tight circles.

How is Low Sperm Motility Diagnosed?

Sperm motility is typically assessed during a semen analysis, one of the first tests used to evaluate male fertility. This laboratory test measures several aspects of sperm health, including:

• Sperm count, or the number of sperm present
• Motility, which reflects how well sperm move
• Morphology, or the shape and structure of sperm

Low sperm motility is generally diagnosed when less than 32 percent of the sperm move as they should.

If abnormalities are detected, additional testing may sometimes be recommended. Depending on the situation, this could include hormone testing, imaging, and/or genetic testing.

What Can Cause Low Sperm Motility?

There are several possible reasons sperm may have difficulty moving properly. In many cases, more than one factor may be involved. Some issues may include:

Varicocele

A varicocele is an enlargement of the veins that drain blood from the testicles. It’s not exactly clear why varicocele impacts fertility, but specialists think that the condition may raise the temperature around the testicles, which can interfere with normal sperm development.

Hormonal Imbalances

When the hormones that regulate sperm production become imbalanced, the body may have difficulty producing healthy sperm.

Infections

Sexually transmitted infections and infections that cause inflammation of the testicles or epididymis may impact sperm movement. While most infections resolve without long-term complications, repeat or particularly severe infections can lead to scarring or damage of reproductive tissue, negatively impacting fertility.

Lifestyle Factors

Everyday habits can also play a role in sperm health. For example, smoking and excessive alcohol use have been associated with reduced sperm quality and motility. Poor diet and obesity have also been linked to poor sperm health.

Genetic Conditions

Some inherited genetic conditions, such as Klinefelter syndrome, can affect the development or function of the male reproductive system.

Treatment Options for Low Sperm Motility

Treatment for low sperm motility often depends on the underlying cause. In many cases, addressing contributing factors can help improve sperm health and fertility.

• Lifestyle Changes: Maintaining a balanced diet, achieving a healthy weight, limiting alcohol consumption, and avoiding tobacco use have all been shown to support sperm health.
• Medication: If hormonal imbalances or infections are identified, medications or other medical treatments may be recommended to address the underlying issue and support normal sperm production.
• Varicocele Repair: For individuals with a varicocele, a minor surgical procedure may be performed to repair the affected veins.
• Assisted Reproductive Techniques: When sperm motility remains low, several assisted reproductive technologies may be recommended to achieve pregnancy. This may include intrauterine insemination (IUI), in which sperm is collected and prepared in the laboratory, and then placed directly into the uterus, increasing the chances of reaching the egg. Depending on the factors impacting fertility, some may benefit from IVF, in which fertilization takes place in the laboratory, and the resulting embryo is placed directly into the uterus. During IVF, your provider may also recommend intracytoplasmic sperm injection (ICSI), in which a single sperm is injected directly into the egg during fertilization.

When to Seek an Evaluation

Low sperm motility can make conception more challenging, but it does not mean pregnancy is out of reach. If you and your partner are under the age of 35 and have not achieved pregnancy after a year of unprotected sex, it may be time to seek a fertility evaluation. With the right evaluation, many underlying causes can be identified and treated. At Male Fertility Specialists, our team works closely with patients to evaluate sperm health, identify contributing factors, and develop a treatment plan tailored to your needs and goals. If you’ve been trying to conceive or have questions about male fertility, scheduling a consultation is an important first step toward understanding your options.