

Many people mistakenly refer to it as “lazy sperm,” but the correct term is asthenozoospermia. Asthenozoospermia (not to be confused with azoospermia) is a condition in which sperm motility is below the optimal levels recommended by the World Health Organization (WHO).
The WHO considers normal values to be over 32% progressive motility (sperm that move forward) or over 40% total motility (sperm with and without forward movement).
Asthenozoospermia in Male Infertility
Asthenozoospermia is one of the main causes of male infertility, since this alteration in sperm motility prevents sperm from reaching and fertilizing the egg, resulting in pregnancy failure.
Unfortunately, asthenozoospermia has no associated symptoms. The only way to diagnose it is through a semen analysis or spermogram.
To make an accurate diagnosis, two abnormal spermograms are required, performed 2–3 months apart, to ensure that the alteration is not due to a single isolated episode.
Causes of Asthenozoospermia
The causes of asthenozoospermia are varied and not precisely known, but several factors and situations have been linked to reduced sperm motility:
- Stress
- Excessive consumption of alcohol, tobacco and other drugs
- Exposure to toxic agents (fertilizers, etc.)
- Exposure of the testicles to high temperatures (chefs, saunas, etc.)
- Infections
- Testicular varicocele
- Chemotherapy and radiotherapy
- Advanced age
- Unhealthy lifestyle habits
Is There a Treatment for Asthenozoospermia?
Although there is no definitive cure, vitamin and antioxidant supplements are often prescribed to improve sperm motility, typically taken for about three months.
After this period, a new semen analysis is performed to assess whether motility has improved.
Depending on the degree of asthenozoospermia (mild or moderate), pregnancy may still occur naturally, although it usually takes longer than in the absence of the condition.
Fortunately, there are assisted reproduction techniques available to help couples achieve pregnancy when asthenozoospermia is present. Fertility treatments to achieve pregnancy in cases of asthenozoospermia include
- If the degree of asthenozoospermia is very mild, artificial insemination (AI) may be considered. In this procedure, a prepared semen sample from the partner or a donor is introduced into the woman’s uterus at the time of ovulation. This method is recommended only for women under 35 years of age and only when no other cause of infertility has been detected.
- If the degree of asthenozoospermia is mild, in vitro fertilization (IVF) may also be considered. This technique allows the patient’s eggs to be combined with a higher-quality sperm sample in a special laboratory dish under controlled conditions to increase the chances of successful fertilization.
- In moderate or severe cases of asthenozoospermia, the most effective treatment to achieve pregnancy is intracytoplasmic sperm injection (ICSI), which ensures that one sperm is injected directly into each egg.
The treatment of asthenozoospermia should always be complemented with healthy lifestyle advice, which in some cases can help restore fertility.
Book a free consultationDo you have any questions or need more information?
At Fertility Madrid, we specialise in treatments such as egg donation, in vitro fertilisation and artificial insemination, among others.
Please do not hesitate to contact our professionals at our fertility clinic and they will answer all your questions without obligation.