Understanding Medical Aspects of Infertility: the Cervix and the Uterus

Polyps
Polyps are overgrowths of the endometrium that almost resemble stalactites in a cave. They also can result in effects much like an IUD, and may also be associated with abnormal bleeding.

Scarring
Sometimes after a D&C, particularly if it is done around the time of a pregnancy, scarring may occur. One wall of the uterus actually sticks to the other wall. This is known as intrauterine synechiae, or Asherman's syndrome. This scarring may be minimal, with just a small band of scar tissue, or severe, at times almost obliterating the entire uterine cavity.

Knowledge in much of this area is being gained rapidly, but is relatively new. There are a few problems we can discuss.

Luteal Phase Defect
This is a defect in which the endometrium either is not exposed to enough progesterone or does not respond properly to the progesterone that is produced. As a result, the cells of the endometrium do not undergo the very orderly series of changes that they must undergo to allow implantation to occur. Consequently, even if a conception does occur, the endometrium may not be ready to accept it and, therefore, implantation will not occur. In the past, this has been diagnosed by an endometrial biopsy, an invasive and sometimes painful procedure in which a small piece of the lining of the uterus is removed and analyzed for proper development under the microscope.

You do not necessarily need to have an endometrial biopsy for purposes of diagnosing a luteal phase defect. Adequate progesterone production can be very easily diagnosed with a simple blood test. Even if there may be some rare individuals whose endometrium does not mature properly even with normal progesterone levels, the treatment is the same as that for patients who have unexplained infertility. Therefore, there is really no need to have a biopsy. Furthermore, if you do have a biopsy and some treatment is initiated to correct a problem, a repeat biopsy to evaluate the effectiveness of that treatment is needed. Don't do it! Rather than having multiple biopsies to establish the diagnosis of luteal phase defect, serum progesterone levels can be used.

Thin Endometrium
The endometrium is another tissue that grows in response to estrogen. If the effect of estrogen is blocked, the endometrium may not develop adequately. This can sometimes occur as a result of the use of clomiphene. Normal endometrium usually develops to a thickness, as measured by ultrasound, of around 10 millimeters. If it develops to only seven millimeters or less, pregnancy is extremely rare. The tissue just hasn't developed enough to allow it to accept a pregnancy. Endometrial development should be assessed by ultrasound in women on clomiphene, particularly if higher doses are being used, and any time gonadotropins are used.

Integrins
Integrins are proteins that are very "sticky." They play a role in the adhesion of one cell to the next and are important in the implantation process. Although a defect in their production appears to be a rare phenomenon, it apparently can occur. Assays for integrins may soon be available. This test does require an endometrial biopsy, and in couples with difficult unexplained infertility, this may be worthwhile.