Ultrasound is used by a physician to “see” structures in the female abdomen and pelvis. Ultrasound uses high frequency sound waves much like SONAR machines used in ships for detecting submarines underwater. With ultrasound, high frequency sound waves are emitted by a “probe” (also called a transducer). The sound waves bounce off the organs and tissues in the body and the reflected sound waves are received by the probe and a computer is used to reconstruct the waves into images on the monitor.
In the past, ultrasounds were performed using a probe that rested on the surface of the abdomen. This type of ultrasound requires a full bladder so that the sound waves could be transmitted more easily into the pelvis. This type of ultrasound is still used today for ultrasound guidance during an an embryo transfer.
Just about every other type of infertility ultrasound is done using a vaginal ultrasound probe in which a long, slim, ultrasound probe is inserted into the vagina. This is similar in size to a vaginal speculum that doctors use in order to perform a PAP smear. The image quality is superior with vaginal ultrasound since the ultrasound probe is much closer to the pelvic organs like the uterus and ovaries.
Ultrasound for pelvic abnormalities
An infertility ultrasound is an important first test for any women experiencing difficulty conceiving. First, an infertility ultrasound will verify that the uterus and both ovaries are present. Ultrasound does not reliably detect the fallopian tubes. for this evaluation a hysterosalpinogram is performed. The size, shape and position of the uterus are recorded. Masses within the uterus called fibroids can measured and mapped. The ovaries can also be measured. The size of the ovaries as well as the number of follicles present are an important determinant of a woman’s ovarian reserve .
A common abnormal finding on an infertility ultrasound is ovarian cysts. Most often, ovarian cysts are simply evidence of a growing egg or evidence of recent ovulation. On occasion, however, a cyst may represent an abnormality such as endometriosis .
Finally, although normal fallopian tubes are usually not seen on an infertility ultrasound, a type of abnormal fallopian can be seen. Occasionally, if the distal end of a fallopian tube become blocked, the tube will fill with fluid. This is called a hydrosalpinx. It is important to determine the presence of a hydrosalpinx since the presence of hydrosalpinges will indicate not only blocked fallopian tubes but also reduce the success rate of treatments such as IVF.
Ultrasound for monitoring infertility treatments
The most common treatments used for infertility employ the use of fertility medications . These medications stimulate the development of eggs in the ovaries. The eggs grow inside of the follicles. The follicles fill with fluid and enlarge while the egg is developing. The size and number of these developing follicles can be accurately determined with infertility ultrasound. In this way, the physician can determine the appropriate time to either trigger ovulation or perform an IVF egg retrieval.
Infertility ultrasound is also used to monitor the growth and development of the uterine lining. while most of the uterus is composed of muscle, the innermost layer which surround the uterine cavity is made of glandular tissue. Under the influence of hormones produced from the ovaries, the uterine lining will grow and thicken. The thickness of the uterine lining can be measured and patterns of appearance can be seen.