Asthenozoospermia (or asthenospermia) is the medical term for reduced
sperm motility
Motility is the ability of an organism to move independently, using metabolic energy.
Definitions
Motility, the ability of an organism to move independently, using metabolic energy, can be contrasted with sessility, the state of organisms th ...
. Complete asthenozoospermia, that is, 100% immotile spermatozoa in the ejaculate, is reported at a frequency of 1 of 5000 men.
Causes of complete asthenozoospermia include
metabolic deficiencies, ultrastructural abnormalities of the sperm flagellum (see
Primary ciliary dyskinesia) and
necrozoospermia.
[
It decreases the sperm quality and is therefore one of the major causes of ]infertility
Infertility is the inability of a person, animal or plant to reproduce by natural means. It is usually not the natural state of a healthy adult, except notably among certain eusocial species (mostly haplodiploid insects). It is the normal st ...
or reduced fertility in men. A method to increase the chance of pregnancy is ICSI.[ The percentage of viable spermatozoa in complete asthenozoospermia varies between 0 and 100%.][
]
DNA fragmentation
Sperm DNA fragmentation
DNA fragmentation is the separation or breaking of DNA strands into pieces. It can be done intentionally by laboratory personnel or by cells, or can occur spontaneously. Spontaneous or accidental DNA fragmentation is fragmentation that gradually a ...
level is higher in men with sperm motility defects (asthenozoospermia) than in men with oligozoospermia or teratozoospermia.
Asthenozoospermia and DHA
In 2015, Eslamian et al. found a correlation between the composition of the sperm lipid membrane and the odds of having asthenozoospermia. The sperm that have more polyunsaturated fatty acids, such as docosahexaenoic acid (DHA) shown better fertility results.
DHA (docosahexaenoic acid) is an acid formed by six double bonds which allows the fluidity of the membrane, necessary for the fusion with the ovule.
Studies in mice have shown that DHA is essential for acrosome reaction and a DHA deficiency results in abnormal sperm morphology, loss of motility and infertility; which can be restored by dietary DHA supplementation.
Furthermore, the supplementation with DHA in humans has been reported to increase sperm motility. But also, DHA supplementation can protect spermatozoa against the damage caused by the cryopreservation process.
References
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External links
GP Notebook
Testicular infertility factors
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