Sperm morphology-sperm abnormalities

Sperm morphology test evaluates the shape of sperm cell. Sperm morphology  is a sub title of semen analysis test which is done to evaluate semen fluid and sperm cell features. Semen analysis test is done to diagnose male type infertility and evaluates so many characteristics of semen and sperm like; sperm viability, semen volume, sperm morphology, sperm concentration, sperm count, sperm motility,semen pH and semen liquefaction time.


Sperm cell is 5-6 micrometers long, 2-3 micrometers wide and has a tail 50 micrometers long. Sperm cell has parts as;

sperm morphology

  • Sperm head; has nucleus and DNA
  • Sperm neck; connects the mid-piece and sperm head, has centrioles and centrosomes, has an important function in fertilizaton of sperm and egg.
  • Sperm mid-piece; contains mitochondria and produces energy for sperm cell
  • Sperm tail (flagellum) provides motility for sperm cell

Sperm morphology- sperm abnormalities

Defect Cause or result Incidence
Normal sperm Only sperm count test can’t say that you can have baby or not Men have child Man can’t have child
Long-thin sperm head Suggests a structural defect in sperm nucleus and DNA or DNA damage. Varicocele increases this type of defect  

< 14%



Small sperm head DNA development insufficiency and DNA damage. Insufficient nucleus protein may be the cause <7% >30%
Double headed sperm May cause genetic anomaly in embryo <2% >9%
Big sperm head Some type of special gene defiencies <1% >5%
Neck anomaly Centrosome defects; may cause problem in egg multiplication during IVF process
Acrosome defect Sperm head development failure because of environmental and genetic causes <60% >95%
Post-acrosome defect <42% >83%
Bent tail Structural defects in testes caused by environmental factors


Men have child Man can’t have child
Excess cytoplasm May cause DNA damage  

< 4%



Thin mid-piece Suggests mitochondria defect, may cause motility failure, DNA damage and necrosis <0% >4%
Sperm head without tail Can’t get pregnant by natural way
Short sperm tail Distrupts sperm motility <1% >14%
Double tailed sperm Distrupts sperm motility <1% >5%
Thick tail or disordered shaped tail May be caused by genetic factors <2% >12%
Spiral shaped tail Caused by epididymis problems, increases in smokers <17% >37%