Understanding Medical Aspects of Infertility: the Cervix and the Uterus

There are several reasons why the cervical mucus may be poor and account for a bad postcoital test:

• Poor Timing of the Test. This is far and away the most common reason that a postcoital test is unsatisfactory. This test must be performed just before ovulation occurs, when the cervical mucus is optimal.
• Prior Procedures on the Cervix. The cervical mucus is produced by the columnar cells that normally line the inside of the cervix. When these cells are damaged or destroyed, the normal repair process replaces them with a type of cell known as squamous cells. These squamous cells are incapable of making cervical mucus. Therefore, destruction of enough of the columnar cells can lead to a dramatic decrease in cervical mucus production.

  Procedures that can result in this type of change include freezing of the cervix, laser to the cervix, lleetz or leep procedures and cervical conizations, all of which are performed to treat abnormal Pap smears.

• Infection. The cells lining the cervix may become irritated or even infected. This will often be indicated by the presence of white blood cells in the mucus.
• Medications. The most notable of these is clomiphene. Clomiphene (common brand name Clomid) can dramatically impair cervical mucus quantity and quality. Anyone on clomiphene, or anyone who has had her dose of clomiphene increased, should have a postcoital test checked. (Clomiphene blocks the effect of estrogen on cells. Estrogen induces the columnar cells in the cervix to produce mucus; therefore clomiphene can block this effect.)

Tetracyclines
The presence of white blood cells suggesting an infection can usually be resolved by treating the woman with an antibiotic. Tetracyclines are most commonly used for this purpose.

Cough Medicines
In certain individuals, there may be some role for cough medicines. Certain cough medicines (e.g., Robitussin) contain substances (e.g., guaifenesin) that actually do help thin out the cervical mucus. Taking a teaspoon three or four times a day for the two or three days before ovulation may result in some thinning of the mucus.

Estrogen
If a woman is on a certain dose of clomiphene and seems to be ovulating well but the cervical mucus is poor, some physicians will prescribe small doses of estrogen. The thinking here is that giving some additional estrogen may override the blocking effect of the clomiphene and improve cervical mucus production. While this approach is safe and easy, if it does not result in significant improvement (as checked by the postcoital test), inseminations should be considered instead.

Inseminations
Inseminations are a means of bypassing the cervical mucus altogether. A semen sample is provided by masturbation and then prepared by the laboratory so that a pure preparation of sperm is suspended in a specially prepared salt buffer. This preparation is then placed in a small syringe that is attached to a small plastic catheter. A speculum is placed in the vagina and the catheter is gently guided through the cervix and into the uterus. This is a painless, nonsurgical procedure and is particularly useful if the mucus-producing cells of the cervix are destroyed or nonfunctional. The cervical mucus is, in essence, bypassed by placing the sperm beyond the cervix and into the uterus.