Sperm morphology- sperm tail

Sperm morphology also called sperm shape is a sub title in semen analysis test. Semen sample is examined to determine features of semen fluid and sperm cell. Semen analysis is a type of laboratory test that is done to diagnose male type infertility. Semen analysis also may be done to determine the success of vasectomy operation which is a type of birth control method.

sperm tail

Semen analysis evaluates so many feautures of sperm cell and semen fluid as listed;


  • Semen volume
  • Semen pH
  • Sperm concentration
  • Sperm count ( total sperm count)
  • Sperm motility
  • Sperm morphology
  • Semen liquefaction time
  • Semen WBC count
  • Semen appearance

Sperm morphology test examines the sperm cell parts to diagnose any defects in any sperm part. Sperm cell has parts as;

  • Sperm head
  • Sperm neck
  • Sperm mid-piece
  • Sperm tail

Sperm morphology- sperm tail

Sperm tail also called flagellum is the last part of a sperm cell and 50 micrometers long. Sperm tail provides motility to sperm cell. Sperm cell swims in semen fluid in vagina to reach the egg and fertilization by the help of liquefaction of semen and sperm tail.

Lack of sperm tail, short, bent, thin or thick sperm tail means that there is an abnormality in sperm morphology. Also multiple sperm tail is an another  abnormal sperm morphology type.

Sperm tail contains microtubules and  inner and outer dynein arms that provides motility to sperm cell. Short sperm tail may suggest that there is an abnormality in sperm tail dynein arms, or in fibrosis sheath. This may be caused by genetic factors and can’t be treated by medication so IVF ( in vitro fertilization; test tube baby) method may be  tried.

Sperm tail defects commonly don’t prevent fertilization of egg and sperm cell but sperm cell can’t swim and reach the egg itself and IVF method is needed. If there is another sperm morphology abnormality found with tail defect, IVF may be unsuccessful. If any sperm tail morphology defect is determined, other parts of the sperm cell should be evaluated carefully.