A pelvic ultrasound is a non-invasive medical imaging technique that uses high-frequency sound waves to create live pictures of the organs inside the pelvis, including the uterus, ovaries, and bladder. This procedure is commonly used to investigate symptoms like pelvic pain, abnormal bleeding, or problems with fertility. If menstruation begins unexpectedly, the scan can usually proceed safely and effectively. While menstrual flow introduces specific considerations for the imaging technician, it rarely necessitates rescheduling the appointment unless the diagnostic goal is severely compromised.
The Two Methods of Pelvic Ultrasound
A pelvic ultrasound is typically conducted using two distinct approaches, often performed sequentially during the same appointment.
Transabdominal (TA) Scan
The Transabdominal (TA) scan involves moving a transducer probe across the lower abdomen. For this technique, a full bladder is usually required. The fluid acts as an acoustic window, pushing gas-filled bowel loops out of the way and allowing sound waves to travel more clearly to the pelvic structures below.
Transvaginal (TV) Scan
The second method is the Transvaginal (TV) scan, which involves inserting a thin, lubricated probe into the vagina. This approach brings the transducer much closer to the reproductive organs, providing significantly clearer and more detailed images of the uterus and ovaries. Unlike the TA scan, the TV scan requires the bladder to be empty. This approach is routinely performed even if the patient is actively menstruating.
Diagnostic Considerations During Menstruation
Menstrual flow primarily impacts the visualization of the uterine cavity during a transvaginal scan. Heavy bleeding can obscure the view within the uterus, making it challenging to clearly assess the endometrium (the lining of the uterus). Blood and tissue can create artifacts on the image, sometimes making it harder to detect small lesions or assess the characteristics of the uterine muscle.
Despite this, performing the ultrasound during menstruation can be diagnostically advantageous in certain clinical scenarios. The early follicular phase, which includes the menstrual period, is often the preferred time for evaluating the uterine cavity for focal lesions. During this time, the endometrium is at its thinnest. This thin lining provides a clearer contrast, making it easier to identify abnormalities like endometrial polyps or submucosal fibroids that might otherwise be hidden by a thicker lining.
Necessary Preparations When Bleeding
If a pelvic ultrasound is scheduled during active menstruation, preparation steps can help ensure the procedure is effective. Patients should communicate with the sonographer upon arrival regarding the heaviness of their flow, as this helps the technician anticipate potential imaging challenges. For the transvaginal examination, any internal menstrual products, such as a tampon or menstrual cup, must be removed immediately before the scan begins.
Wearing comfortable, two-piece clothing is also helpful, as it allows for easy access to the lower abdomen for the transabdominal scan and maintains privacy during the transvaginal component. The sonographer will provide a sheet or covering to ensure patient modesty throughout the process. Patients should not feel embarrassed about their period, as imaging staff are accustomed to performing these examinations regardless of the patient’s menstrual cycle day.