A transvaginal ultrasound (TVUS), often called an internal ultrasound, is a common diagnostic procedure used to visualize the female pelvic organs. The procedure involves inserting a specialized probe into the vaginal canal, which allows providers to get detailed images of the uterus, ovaries, and early pregnancy. This imaging technique is widely utilized because it provides a much clearer view of pelvic structures than an external abdominal ultrasound. The transvaginal ultrasound is considered extremely safe, and the risk of infection is statistically very low.
Understanding the Infection Risk
The risk of acquiring an infection from a transvaginal ultrasound is exceptionally rare because the procedure is non-invasive. Unlike surgical procedures or biopsies, the probe does not break the skin or penetrate a sterile body cavity, such as the abdominal space. The probe only contacts the mucous membranes of the vaginal canal, which already hosts a natural population of bacteria, known as flora.
Regulatory bodies classify the device as a “semi-critical” medical device, meaning it must be reprocessed to eliminate all microorganisms. The primary theoretical risk of infection comes from cross-contamination, where organisms from a previous patient are transferred to the next. This can happen if protocols for cleaning and disinfection are not followed rigorously between uses.
In rare cases, an infection linked to the procedure may be due to the introduction of a pathogen already present in the vaginal canal or on the probe itself, such as the human papillomavirus (HPV). The procedure also carries a slightly higher risk of exacerbating existing, undiagnosed conditions, such as pelvic inflammatory disease (PID). This occurs by potentially moving existing bacteria higher into the reproductive tract.
Standardized Infection Prevention Protocols
To mitigate the low infection risk, healthcare facilities follow strict, multi-step protocols mandated for all semi-critical devices. The first protective measure involves using a sterile, single-use physical barrier, such as a latex or non-latex sheath, placed over the probe before insertion. This barrier prevents direct contact between the probe surface and the patient’s mucous membranes.
After the examination, the protective barrier is immediately removed and discarded, and the probe undergoes a two-part reprocessing procedure. The initial step is thorough manual cleaning using specialized detergents to remove all visible gel, debris, and organic matter. This cleaning step is important because any residual matter can interfere with the effectiveness of the next stage, which is disinfection.
The probe then undergoes High-Level Disinfection (HLD), a chemical process designed to eliminate almost all microorganisms. HLD is achieved by soaking the probe in an approved chemical agent, such as hydrogen peroxide or glutaraldehyde, for a specific contact time. Adherence to strict hand hygiene by the technician, including washing hands and wearing gloves before and after the procedure, provides a final layer of protection against accidental contamination.
Identifying Potential Post-Procedure Symptoms
Following an internal ultrasound, most patients experience no significant aftereffects and can resume normal activities immediately. It is common to have a small amount of clear or slightly colored vaginal discharge due to the lubricating gel used during the procedure, which should resolve completely within 24 hours. Some individuals may also feel mild, temporary cramping or minor discomfort similar to period pain, which is typically manageable with over-the-counter pain medication.
Recognizing the signs of a possible infection or complication is important, though these occurrences are infrequent. An infection may be developing if you experience a fever or chills, which are systemic signs of your body fighting off a pathogen. You should also be watchful for severe or worsening pelvic or abdominal pain that does not improve after a day or two.
Unusual vaginal discharge warrants attention, especially if it is foul-smelling, significantly heavier than normal, or contains pus. Heavy vaginal bleeding that is not your normal menstrual flow should also prompt a call to your provider. If any of these concerning symptoms appear, particularly if they persist beyond 24 to 48 hours, you should contact your healthcare provider for evaluation.