As I discussed last week, endometriosis is a very common condition – affecting anywhere from 6-10% of all women of reproductive age and up to 45% of infertile women. It is well known that endometriosis can cause infertility, although it has not been identified as a cause of recurrent pregnancy loss. Despite this, it is commonly overlooked during the infertility evaluation.
Although some women present with classic endometriosis symptoms, including increasingly severe pain with periods, pain with intercourse, and generalized pelvic pain that is usually worse just before the onset of a period, many women who have significant endometriosis have no symptoms at all. This can often confuse patients and uninformed physicians alike, as most medical conditions produce symptoms that worsen as the disease worsens. This is just not true with endometriosis. In fact, many studies have shown that the severity of symptoms and the severity of this disease often have nothing to do with each other; women with severe disease may have no symptoms while women with minimal disease can have excruciating pain. This can make the diagnosis of endometriosis quite challenging.
Over the years, researchers have discovered several types of tests designed to detect the presence of endometriosis. Blood tests, such as the CA 125 assay – while often abnormal in the presence of endometriosis – are simply not reliable. Many women with severe endometriosis have normal CA125 levels. In addition, several other conditions such as ovarian cysts, ovarian cancer, or uterine fibroids can cause an abnormal elevation of CA125. Therefore, although this test once held promise as a good diagnostic tool, more recent studies have demonstrated that it is not helpful and it is now very rarely used to detect endometriosis.

Although there is no accurate blood test to use when making the diagnosis of endometriosis, many radiologic studies – such as ultrasound, CT scanning, and magnetic resonance imaging (MRI) – have been shown to be very good at detecting or confirming the presence of endometriosis, especially if an ovarian mass is present. Ultrasound, specifically transvaginal ultrasound, is the simplest and the least expensive of these techniques. This exam involves the painless placement of a camera, or probe, into the woman’s vagina. Sound waves are then produced which pass through the woman’s pelvis and back into the camera. These reflected sound waves generate images on a TV monitor that allow physicians to non-invasively visualize the organs in the pelvis, including the uterus and the ovaries. An endometrioma (or cyst made of endometriosis fluid) usually appears as a round mass within an ovary. It has white or gray echoes when seen with ultrasound, in contrast to a follicle which is usually solid black. Both CT and MRI examinations are much more expensive than ultrasound. In addition, they have to be scheduled with a radiology office or hospital, which is much more difficult than an ultrasound, which can be easily scheduled in an RE or OB/GYN office. For these reasons, CT and/or MRI are only rarely ordered.
The only truly accurate diagnostic test is laparoscopy. This involves the passage of a surgical telescope through a woman’s belly button so that the pelvic organs can be actually seen. I will discuss this technique more in the next blog, so please check back to learn more about endometriosis and how it can affect your fertility.