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Sperm Penetration Tests

Results continued...

A problem with the partner's sperm may be present if:

  • The donor's sperm penetrates the mucus but the partner's sperm does not.
  • The partner's sperm does not penetrate the woman's or the donor's cervical mucus.

A problem with the woman's mucus may be present if neither the partner's or the donor's sperm do not penetrate the cervical mucus.

Sperm mucus penetration test1

Sperm penetrate the cervical mucus and move through it easily.


Sperm cannot penetrate the cervical mucus or they clump together in the mucus. Clumping may mean that the woman or man has developed antibodies against the sperm. If the sperm antibodies are from the man's body, clumping may also be seen in his semen analysis.


Sperm penetration assay (SPA)

Results are based on the number of sperm that can penetrate an egg and can vary from lab to lab. Talk with your doctor about whether your results are normal.

Sperm penetration assay (SPA)

Sperm penetrate the hamster egg.


Sperm cannot penetrate the hamster egg.


What Affects the Test

Reasons you may not be able to have the test or why the results may not be helpful include the following:

  • The semen sample has not been collected correctly.
  • The test is done at a time when a woman is not ovulating.

What To Think About

  • The sperm penetration assay test may be done before in vitro fertilization.
  • A normal sperm penetration assay and a normal semen analysis mean that the sperm is of good quality for in vitro fertilization. To learn more about infertility testing, see the topic Infertility Testing.

Related Information


  1. Pagana KD, Pagana TJ (2010). Mosby’s Manual of Diagnostic and Laboratory Tests, 4th ed. St. Louis: Mosby Elsevier.

Other Works Consulted

  • Fritz MA, Speroff L (2011). Male infertility. In Clinical Gynecologic Endocrinology and Infertility, 8th ed., pp. 1249–1292. Philadelphia: Lippincott Williams and Wilkins.

  • Lobo RA (2012). Infertility: Etiology, diagnostic evaluation, management, prognosis. In GM Lentz et al., eds., Comprehensive Gynecology, 6th ed., pp. 869–895. Philadelphia: Mosby.

ByHealthwise Staff
Primary Medical ReviewerSarah Marshall, MD - Family Medicine
Specialist Medical ReviewerFemi Olatunbosun, MB, FRCSC - Obstetrics and Gynecology
Current as ofMarch 12, 2014

WebMD Medical Reference from Healthwise

Last Updated: March 12, 2014
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.

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