Asthenozoospermia

Asthenozoospermia is the medical term for the reduced sperm motility in a man’s semen sample. This condition compromises the patient’s fertility by preventing the sperm from reaching and fertilizing the egg.

In-Vitro Fertilization (IVF) coupled with Intracytoplasmic Sperm Injection (IVF + ICSI) is a specialized procedure where a single sperm is carefully introduced directly into the cytoplasm of a mature egg using a microscopic needle via micromanipulation. This technique offers the highest pregnancy rates by disregarding sperm motility as a necessity to fertilize the egg. This is thus the best option for couples with asthenozoospermia.

What is asthenozoospermia?

Asthenozoospermia is the medical term for the reduced sperm motility in a man’s semen sample.

According to the World Health Organization (WHO), this condition is diagnosed when the percentage of progressively motile sperm is below 50 percent or when the number of motile rectilinear-trajectory sperm with speed of 25 micrometers per second is less than 25 percent.

Asthenozoospermia is the most frequent seminal alteration. This condition compromises the patient’s fertility by preventing the sperm from reaching and fertilizing the egg.

Asthenozoospermia causes

Although asthenozoospermia causes are not exactly known, it is recognized that sperm motility may be affected by factors such as:

  • Teratozoospermia
  • Varicocele
  • Seminal tract infections
  • Testicular problems
  • Antisperm antibodies
  • Poor nutrition habits
  • Smoking
  • Excessive alcohol, coffee or tobacco consumption (or other drugs such as cocaine and marijuana)
  • Exposure to toxic agents such as solvents or insecticides
  • Age (sperm mobility decreases after a man reaches 45)
  • Oncologic (cancer) treatments such as chemotherapy and radiotherapy
  • Febrile episodes
  • Prolonged heat exposure in automobiles, saunas or hot tubs

How is asthenozoospermia diagnosed?

Asthenozoospermia can be diagnosed through a simple spermiogram (or semen analysis). This test is performed following a 3-5-day sexual abstinence period.

For fertilization to occur the percentage of progressively motile sperm must be greater than 50 percent and the number of motile rectilinear-trajectory sperm with speed of 25 micrometers per second must exceed 25 percent.

Treatments to achieve pregnancy in patients with asthenozoospermia

Fertility treatments to achieve pregnancy when suffering asthenozoospermia include:

  1. Artificial insemination, where a previously capacitated couple or donor sperm sample is introduced into the woman’s uterus just at the time of ovulation. This method is only recommended in women under 35 and only when there are no other detected infertility causes. 
  2. In-Vitro Fertilization (IVF), which allows to join the patient’s eggs with an improved quality sperm sample in a special laboratory dish under controlled conditions to increase the likelihood of a successful fertilization.
  3. In-Vitro Fertilization (IVF) and Intracytoplasmic Sperm Microinjection (IVF + ICSI). In this specialized procedure a single sperm is carefully introduced directly into the cytoplasm of a mature egg using a microscopic needle via micromanipulation. This technique offers the highest pregnancy rates by disregarding sperm motility as a necessity to fertilize the egg. This is thus the best option for couples with severe asthenozoospermia.

Asthenozoospermia treatment should always be complemented by healthy lifestyle advices, which in some cases can help restore fertility.