A sonohysterogram, also known as Saline Infusion Sonography (SIS), is a specialized pelvic ultrasound that provides a detailed view of the uterine lining (endometrium). The procedure involves gently infusing sterile saline solution into the uterine cavity, which separates the walls and allows visualization of irregularities such as polyps, fibroids, or scar tissue. The total appointment time, including check-in and preparation, generally ranges from 30 to 60 minutes. However, the active procedure time, when instruments are in the body, is typically brief, lasting only 5 to 15 minutes.
Essential Pre-Procedure Steps and Scheduling
The timing of a sonohysterogram is controlled to maximize image quality and minimize risks. Clinicians typically schedule the test between day six and day ten of the menstrual cycle, immediately after bleeding has stopped. This window is chosen because the uterine lining is thinnest, making it easier to identify small abnormalities. Scheduling it early also ensures the patient is not pregnant, as the procedure is contraindicated during pregnancy, and a pregnancy test is often administered beforehand.
Patients are advised to take an over-the-counter pain reliever, such as ibuprofen, 30 to 60 minutes before the appointment. This pre-medication helps mitigate mild cramping experienced when the catheter is inserted and saline is infused. Some facilities may administer prophylactic antibiotics, especially for patients with specific medical histories, to reduce the risk of pelvic infection. Patients should arrive with a full bladder for an initial transabdominal scan, but they will be asked to empty it completely before the transvaginal procedure.
The Step-by-Step Duration of the Sonohysterogram
Time spent in the procedure room begins with check-in, consent review, and changing into a gown, usually taking 5 to 10 minutes. Once positioned, the first active step is the baseline transvaginal ultrasound, performed before saline introduction. This initial scan assesses the basic structure and position of the uterus and ovaries, typically requiring 3 to 5 minutes.
Following the baseline scan, a speculum is inserted to visualize the cervix, similar to a Pap smear. The cervix is cleansed with an antiseptic solution to maintain a sterile environment and prevent infection. A thin, flexible catheter is then gently passed through the cervical opening into the uterine cavity. This stage, including speculum insertion and catheter placement, is often the most uncomfortable part of the test but is completed swiftly, taking 3 to 7 minutes.
Once the catheter is secured, the speculum is removed, and the transvaginal ultrasound probe is reinserted. Sterile saline solution is slowly infused through the catheter, distending the uterine cavity for complete visualization of the endometrial lining. The actual imaging portion, where the walls of the uterus are separated by the fluid, is rapid and lasts 3 to 5 minutes. The entire sequence, from speculum insertion to probe removal, constitutes the active procedure time, generally confined to 10 to 15 minutes.
What to Expect Immediately After the Procedure
After imaging is complete and instruments are removed, the patient may experience immediate physical sensations. Mild cramping, often similar to menstrual pain, is common and results from the saline distending the uterus. This cramping is usually temporary, subsiding within minutes to an hour, and is managed effectively with the pre-procedure pain medication.
A watery discharge is routine immediately following the procedure, as the sterile saline solution leaks out. A sanitary pad is recommended for comfort, but tampons should be avoided for the rest of the day. Light spotting may occur for up to 24 hours due to minor cervical irritation. Most patients resume normal daily activities, including driving or returning to work, without restrictions. While preliminary findings may be discussed immediately, a detailed report is typically sent to the referring doctor within a few business days.