A saline ultrasound, also known as saline infusion sonography (SIS) or sonohysterography, is a specialized ultrasound procedure. It provides a more detailed view of the uterine cavity than a standard ultrasound. Sterile saline solution is introduced into the uterus, gently expanding its walls. This allows for clearer visualization of the uterine lining and internal structures, helping identify abnormalities that might otherwise be difficult to detect.
Reasons for a Saline Ultrasound
A saline ultrasound is often recommended to investigate gynecological concerns when standard ultrasound imaging does not provide sufficient detail. It is frequently used to explore causes of abnormal uterine bleeding, such as heavy, prolonged, or irregular periods. This procedure helps distinguish between different types of growths or abnormalities contributing to these bleeding patterns.
The technique is also valuable in evaluating infertility and recurrent pregnancy loss. By offering a clear view of the uterine cavity, it helps identify structural issues that could hinder conception or successful embryo implantation. These issues include uterine polyps (growths of the uterine lining) or submucosal fibroids (non-cancerous growths within the uterine wall that protrude into the cavity).
Furthermore, a saline ultrasound can detect intrauterine adhesions (scar tissue) or congenital anomalies (structural abnormalities present from birth). It can also precisely locate and characterize abnormalities previously seen on a regular ultrasound. This detailed assessment helps healthcare providers understand the underlying cause of symptoms and plan appropriate treatment.
Understanding the Procedure
A saline ultrasound is typically scheduled after menstruation but before ovulation, usually between day 5 and day 12 of your menstrual cycle. This timing minimizes the risk of performing the test during an early, undetected pregnancy and ensures the uterine lining is thin for better visualization. Taking an over-the-counter pain reliever, such as ibuprofen, about 30 to 60 minutes before the appointment can help manage potential cramping.
The procedure begins with the insertion of a speculum to visualize the cervix, which is then gently cleansed with an antiseptic solution. A thin, flexible catheter, typically about 2 millimeters in diameter, is carefully threaded through the cervix and into the uterine cavity. Once the catheter is correctly positioned, the speculum is often removed for increased patient comfort.
Sterile saline solution is then slowly infused through the catheter into the uterus, gently expanding the uterine cavity. Simultaneously, a transvaginal ultrasound probe is inserted to capture detailed, real-time images of the uterine lining and internal structures as the saline fills the uterus. The entire process typically takes about 15 to 30 minutes.
What to Expect and Potential Findings
During a saline ultrasound, you might experience sensations similar to menstrual cramping or pressure as the saline solution is infused. While some discomfort is common, severe pain is not typical, and many patients report only mild sensations. The procedure is generally well-tolerated, especially if pain medication was taken beforehand.
After the procedure, mild spotting or a watery discharge is common as the saline naturally drains from the uterus. This discharge may be slightly blood-tinged and can continue for up to 24 hours. Mild cramping is also possible, but it usually subsides shortly after the procedure. You can typically resume normal activities immediately.
The saline ultrasound is a safe, minimally invasive outpatient procedure. While rare, a small risk of pelvic infection exists, occurring in less than 1% of cases. You should contact your healthcare provider if you experience unusual symptoms such as fever, severe pain, or foul-smelling vaginal discharge after the procedure. The images obtained help identify various uterine abnormalities, including endometrial polyps, fibroids, or scar tissue, guiding further evaluation or treatment decisions.