Many women learn they have fibroids when their doctor performs a routine pelvic exam. A uterus that is enlarged or irregular in shape is a sign that a woman may have fibroids. Certain tests help the doctor to be sure of the diagnosis.
Ultrasound. During this test, sound waves too high-pitched to be heard travel from a handheld instrument that is placed gently on the abdomen or in the vagina. The sound waves "bounce" off of internal organs and return to the instrument. This creates a picture of the internal organs that can be seen on a screen. If there are fibroids in the uterus, they can be seen in the picture. The doctor can measure the fibroids and can also see if anything else is causing enlargement of the uterus.
An ultrasound exam usually takes 15 to 30 minutes. The test does not use X-rays and has no known risks. It is safe to do an ultrasound test on a woman who is pregnant. (The handheld instrument is placed on the abdomen of a pregnant woman.) A woman may feel some discomfort because she needs to have a full bladder during the test.
Magnetic resonance imaging (MRI). This test uses powerful magnets to create a picture of the internal organs. It does not use X-rays, and it is not necessary to have a full bladder. The test takes 30 to 45 minutes. MRI tests are not done routinely because they are much more expensive than ultrasound tests. It is safe to do an MRI test on a woman who is pregnant.
What happens during an MRI test?
The woman lies inside a large hollow tube. If she feels uncomfortable in this enclosed space, a mild tranquilizer may help her relax. She may be given earphones to listen to music or earplugs to block out some of the loud noise made by the magnet (which sounds like a muffled jackhammer).
If the doctor suspects fibroids, why might he or she order an MRI test?
The doctor may decide to order an MRI:
if the ovaries are difficult to see during the ultrasound test
if the doctor wants to see the structure of the fibroids in more detail
CT scan. If MRI is unavailable, the doctor may request a CT scan of the pelvis. CT stands for computerized tomography. A CT scan uses X-rays. It is more expensive than an ultrasound test and may not provide any more information than the ultrasound test did. For these reasons, it is rare for a doctor to order a CT scan for suspected fibroids. A woman cannot have a CT scan if she is pregnant.
Hysteroscopy. This test allows the doctor to look directly into the cavity of the uterus. The doctor may decide to do a hysteroscopy if a woman is having heavy bleeding, is having trouble becoming pregnant, or if fibroids are suspected of causing other fertility problems (for example, a miscarriage). A woman cannot have a hysteroscopy if she is pregnant.
What happens during a hysteroscopy?
A thin telescope called a hysteroscope is gently inserted through the cervix and into the uterus. Enlarging the opening of the cervix to insert the hysteroscope can cause cramping and mild bleeding. Doctors generally advise women to take a mild pain medication before and, if necessary, after the procedure.
A hysteroscopy may be done in a doctor's office (with local or no anesthesia) or in an operating room (with local or general anesthesia).
Uterine X-ray. This test is another option for diagnosing fibroids in women who are having bleeding or fertility problems. A woman cannot have a uterine X-ray if she is pregnant.
What happens during a uterine X-ray?
An instrument is gently inserted into the opening of the cervix. Dye is injected, filling the uterus. The doctor can see the shape of the uterine cavity and can take X-ray pictures of the uterus and fallopian tubes. The doctor can see if the tubes are blocked because the dye will not pass through them.
This test may cause cramping. Doctors generally advise women to take a mild pain medication an hour or so before the test, which is done in a radiology suite (with local or no anesthesia). The dye is harmless (unless a woman has an allergy to iodine or shellfish) and it is quickly removed from the body.
Medical names for this test are hysterosalpingogram (or HSG) and uterotubogram.
Endometrial biopsy. In this test, a small piece of the lining of the uterus (the endometrium) is removed and examined under a microscope. The doctor may suggest an endometrial biopsy if a woman is having heavy or lengthy periods. The purpose of the test is to rule out other causes for the bleeding, such as infection, a polyp, or cancer.
What happens during an endometrial biopsy?
A thin tube is gently passed through the cervix to obtain a piece of tissue from the lining of the uterus. This takes only a few minutes. The test may cause cramping. It can usually be performed in a doctor's office with local or no anesthesia.
Dilatation and curettage (D&C). This test is another way to obtain a small (or somewhat larger) piece of the lining of the uterus. It might be done instead of an endometrial biopsy if more tissue is needed or if an endometrial biopsy cannot be done.
What happens during a D&C?
The opening of the cervix is gently enlarged (dilated) by inserting metal probes of increasing thickness. Then, a scraping instrument is passed through the enlarged opening of the cervix to obtain a piece of tissue from the lining of the uterus. A D&C is performed in an operating room. Local or general anesthesia may be used.
The doctor also needs to rule out other problems that can cause the same symptoms as fibroids. For example, an imbalance of hormones may cause heavy periods. A bladder infection can cause a frequent need to urinate.