A gynaecological ultrasound scan is a diagnostic test studying the organs of the pelvis with an ultrasound probe. It is a widely used test; however, there is still a lot of ignorance surrounding it. Some of the most common myths about gynaecological ultrasound scanning are:
- It is done only transvaginally
- It is part of a conventional gynaecological examination
- If done excessively, it can be harmful to the organs in the pelvis
- It cannot be performed if a woman is menstruating
- It cannot be performed on women who have not had penetrative sex
- It is used to study the female reproductive system organs only
- It is a tool to diagnose any female reproductive system disease, both at the oncological and fertility level
1. It is done only transvaginally
Gynaecological ultrasound scans can be transabdominal, transvaginal or transrectal.
In the transabdominal route, the ultrasound probe is placed over the abdomen. In this case, the uterus and ovaries are poorly defined, especially in overweight or obese women.
For a transvaginal scan, the probe is placed inside the vagina. In this case, the pelvic organs are seen in much more detail, and so this is the route of choice.
For the transrectal route, the ultrasound probe is placed through the rectum, which is the final part of the large intestine. This is used when the organs of the pelvis need to be seen in detail and transvaginal ultrasound cannot be performed; e.g. in women who have a very narrow vaginal entrance, those who have not had sexual intercourse, who find it uncomfortable or those who do not want to.
2. It is part of a conventional gynaecological examination
Ultrasound scans are not part of a conventional gynaecological examination. If there are symptoms suggestive of a disease or suspicion during a physical examination (e.g. abdominal palpation or vaginal examination), this test may be requested at any time in a woman's life. Contrary to what happens with mammography or cytology, a scan has not been shown to change the prognosis of diseases such as ovarian or endometrial cancer in women without symptoms.
3. If done excessively, it can be harmful to the organs in the pelvis
Sound waves, not radiation, are emitted to obtain the ultrasound image. This means as many ultrasound scans as necessary can be performed without having any negative effect on the patient.
4. It cannot be performed if a woman is menstruating
If the function of the female reproductive system organs is being studied, in addition to their anatomy, ultrasound scans can be done in different parts of the cycle, including when a woman is menstruating. However, it is true that visualising the cavity may be more difficult on the first day of menstruation. In fact, for women with persistent bleeding or those bleeding during the menopause, it is best to do the test during the bleeding, despite it being done transvaginally.
Normally, the advice is to perform an ultrasound scan just after a period; as this is the best time to study for any disease in the uterine cavity, due to the fact that the endometrium is very thin. If a check is required to see if the patient ovulates, it is best to do so 2 weeks after the previous period, to see the hole left by ovulation in the ovary.
5. It cannot be performed on women who have not had penetrative sex
For girls or adolescents who need this type of test, but have not had a sexual relationship, an abdominal ultrasound scan with a full bladder is tried first. If the image is not good enough for diagnosis, doing it transvaginally or transrectally with an empty bladder will be considered. Women who have not had penetrative intercourse usually have a preserved hymen, so it may be difficult to insert the transvaginal catheter.
If it does not enter easily through the vagina, the transrectal route is considered. The latter is not painful and images very similar to transvaginal ultrasound are obtained. In addition, there is no need for any type of intestinal preparation.
If the vaginal probe can be inserted without pain, even with an intact hymen, this possibility is also considered. If the girl does not want a scan performed either transvaginally or transrectally, a study of the pelvic organs with magnetic resonance imaging can be requested.
6. It is used to study the female reproductive system organs only
All the pelvic organs are visible in a gynaecological ultrasound scan: not only the uterus and ovaries, but bladder and rectum can also be studied.
Some gynaecological diseases also affect the bladder or rectum, such as endometriosis and uterine cancer. Also, women with urination or faecal problems, for example, can have a gynaecological ultrasound scan to assess the bladder walls and movements of the urethra or sphincters in the anus.
Finally, a gynaecological ultrasound scan is sometimes used to identify diseases not directly related to gynaecology, such as bladder or pelvis tumours or those of another origin.
7. It is a tool to diagnose any female reproductive system disease, both at the oncological and fertility level
Despite the test providing a lot of information, sometimes additional tests or a multidisciplinary approach are needed.
For example, this test is not useful to study cervical infection by the human papilloma virus, unless this infection triggers a cervical tumour.
Despite the fact certain ovarian or uterine tumours have a very typical ultrasound image, the final diagnosis is made by pathologists after taking a biopsy sample.
In assessing sterility, ultrasound can study the ovarian anatomy and make an indirect calculation of ovarian reserve; however, the quality of the eggs cannot be determined. Also, in studying fallopian tube permeability, under normal conditions these are not usually seen by ultrasound without using a specific contrast.
NEWS ARTICLE BY:
Dr. Cristina Ros, gynaecologist at the Gynaecology Service of the Clinical Institute of Gynaecology, Obstetrics and Neonatology, Hospital Clínic Barcelona