Scheduling a pelvic ultrasound often raises the question of whether the procedure can be performed during menstruation. A pelvic ultrasound is a non-invasive imaging technique that uses sound waves to create pictures of the organs in the lower abdomen, primarily the uterus, ovaries, and bladder. Since these procedures are often scheduled weeks in advance, it is reassuring to know that menstruation rarely prevents the examination from taking place. The ability to proceed depends mainly on the type of ultrasound being performed and the specific medical information the doctor needs to gather.
Pelvic and Transvaginal Ultrasound During Menstruation
A pelvic ultrasound often involves two methods: a transabdominal scan and a transvaginal scan. The transabdominal scan involves placing a transducer on the lower abdomen, and the results are generally unaffected by the presence of menstrual flow. This external approach provides a broader view of the pelvic structures, including the general size and position of the uterus and ovaries.
A transvaginal ultrasound provides much more detailed, high-resolution images because a slender, wand-like transducer is inserted directly into the vagina, positioning it closer to the reproductive organs. This procedure is safe to perform during menstruation. Medical professionals are highly accustomed to performing these examinations regardless of a patient’s menstrual status.
While menstruation does not prevent the scan, the visibility of the uterine cavity may be slightly obscured by a heavy flow, particularly on the first day. The blood and shed tissue can act as a barrier, making it more challenging to clearly visualize the endometrium, which is the lining of the uterus. Despite this limitation, the images of the ovaries, fallopian tubes, and the outer layer of the uterus can still be obtained with high quality.
When Menstruation is Medically Relevant for Diagnosis
In some instances, the timing of the ultrasound during the menstrual period is not just permissible, but is actively sought out by the physician for specific diagnostic purposes. This timing is especially relevant when doctors need to evaluate the endometrial lining inside the uterus. The first few days of the menstrual cycle, known as the early follicular phase, are when the endometrium is naturally at its thinnest after shedding.
Scanning at this time provides a clearer view of the uterine cavity, making it significantly easier to detect subtle abnormalities. Conditions such as endometrial polyps or small submucosal fibroids, which are growths protruding into the cavity, are simpler to spot against a thin background. If the lining were thicker, as it is later in the cycle, these growths might be hidden.
Furthermore, an early cycle ultrasound is a standard requirement in fertility assessments, often called a baseline scan. Performing the scan during the period allows the sonographer to count the small, resting follicles in the ovaries, known as the antral follicle count. This count provides a representation of the ovarian reserve, which is significant information for planning fertility treatments.
Preparing for the Ultrasound Appointment
If your ultrasound appointment falls during your period, there are simple, practical steps you can take to prepare for the examination.
- Wear comfortable, two-piece clothing that allows easy access to the lower abdomen.
- Be prepared to remove any menstrual product, such as a tampon, just before the transvaginal part of the scan.
- Bring an extra sanitary pad to use immediately after the procedure.
- Communication with the technician is important, and you should let them know if you are menstruating.
Bladder preparation varies depending on the type of scan ordered. For a transabdominal scan, a full bladder is typically required to help push the bowel out of the way for clearer images of the pelvic organs. In contrast, the transvaginal scan is performed with an empty bladder for patient comfort and optimal imaging. Always confirm the specific bladder preparation instructions when you book your appointment.