Abnormal Cervical Mucus

Infertility is diagnosed in a couple who have been actively trying to conceive over a course of a year but is unsuccessful.  Infertility is attributable to the female when there are problems with ovulation, damage to the reproductive anatomy (eg uterus, fallopian tubes), or in the presence of an abnormal cervical mucus.

The cervical mucus plays a significant role because it facilitates the sperm in reaching the egg cell.  Therefore, abnormal cervical mucus may make it more challenging for a sperm to reach the egg and could even prevent penetration of the sperm with the egg, preventing fertilization.

Pathophysiology

Prior to ovulation or the release of the mature egg cell from the ovary, the levels of the sex hormone estrogen is high, while that of progesterone is low.  Estrogen affects the cervical mucus by causing it to be thin, watery, and stretchable (elastic), which allows progressive forward movement of the sperm through the cervix.  The pH level of the mucus at this time also becomes more alkaline (higher pH than the usual low pH level or acidic), making the environment more conducive for sperm survival.

Abnormal cervical mucus may be very thick, causes limitation in motion and penetration of the sperm.  It may also promote destruction of the sperm due to the possible presence of antisperm antibodies or inflammatory cells, resulting in nonmotile sperm or destruction of sperm.  The pH level also tends to be lower (acidic) which may destroy or inactivate the sperm.

Abnormal cervical mucus can be the cause of any process interfering with the anatomy and function of the cervix and its glands.  Examples are cervicitis (infection of the cervix), or previous surgery to the cervix (conization or cauterization).

Diagnosis

The Simms-Huhner test, more commonly known as the postcoital test, examines the cervical mucus for the presence and number of motile sperm 2 to 10 hours after sexual intercourse.

The cervical mucus test is examined for the volume, consistency, ferning, spinnbarkeit (elasticity property of the mucus), and cellularity (less cellularity is more advantageous). 

Treatment

Thick cervical mucus can be treated by oral Guiafenesin, which the active component of Robitussin (a cough preparation).  This is a mucolytic medication which helps lyse the mucus.  If an infection has been confirmed, the appropriate antibiotics are administered.  Oral estrogen medication given 8 to 9 days before ovulation may increase mucus production and possibly improve its quality.  In the presence of antisperm antibodies, steroids may inhibit the woman’s immune system.  Lubricants such as KY jelly are discontinued because they can be toxic to the sperm and impair survival.

References:

http://www.merckmanuals.com/professional/sec18/ch256/ch256c.html

http://www.docshop.com/education/fertility/causes/female/hostile-cervical-mucus

http://www.fertilityjourney.com/trying-for-a-while/female-infertility/hormonal-imbalance/index.asp?C=55586405297653472222#abnormalcervicalmucus5

Check JH. Clin Exp Obstet Gynecol 2010. 37(3):169-74.

Check JH. Clon Exp Obstet Gynecol 2006. 33(3):140-2.

Stanislavov R, et al. Akush Ginekol (Sofiia) 1999. 38(4):30-2.