Sperm motility means sperm cells’ movement ability. Sperm cells should have a proper motility to pass vagina, reach the egg and fertilize it. Sperm cells enter the vagina during ejaculation inside the semen fluid. Semen is thick and gel like at the beginning of ejaculation to avoid sperm cells move out vagina. After 20-30 minutes semen fluid liquefies and provides sperm cells a fluid to swim inside. Also semen fluid protect sperm cells from acidic vaginal environment.
Sperm cells swim in semen fluid through the vagina by the help of their tails. There are 2 types of sperm motility as
Progressive motility; that sperm cells move on a straight line to the egg, this is the normal sperm motility and 32% of sperm cells should have progressive motility.
Non-progressive motility; sometimes sperm cells move in abnormal ways. Sperm cells swim in tight circles and can’t move on a straight line to the egg.
Normal sperm motility values
- At least 40% of sperm cells should be motile, this value includes all moving sperm cells as progressive and non-progressive motile.
- 32% of motile sperm cells should be progressive motile
- Sperm cells should have progressive motility and travel 25 micrometers a second
Low sperm motility causes
Low sperm motility also called asthenospermia or asthenozoospermia. Asthenospermia is a cause of male type infertility and may be found with oligospermia (low sperm count) and morphologic defects at the same time. Low sperm motility may be caused by several reasons and life style factors;
- Genetic problems like Kleinfelter’s syndrome
- Sperm production problems
- Poor diet, mineral and vitamin deficiencies like zinc, vitamin C, selenium
- High temperature; saunas, hot tubs may increase testicular temperature
- Tight clothes
- Smoking causes asthenospermia and also low sperm count
- Defects in sperm tail
- Undescended testicles
- Testicular surgery
- Testes cancer
- Drug usage like cocaine, marijuana
- Hormonal disorders
- Toxic materials, chemicals
- Anabolic steroids
- Pelvic trauma
- Infrequent ejaculation
- Varicocele ; enlaregement of scrotum veins