What Is a Saline Infusion Sonography (SIS) and Do You Need One Before IVF?

What Is Saline Infusion Sonography?

Saline infusion sonography, also known as sonohysterography or SIS, is a specialised ultrasound examination that provides detailed visualisation of the uterine cavity. This minimally invasive procedure combines traditional transvaginal ultrasound with the gentle infusion of sterile saline solution into the uterus, creating optimal contrast to evaluate the endometrial lining and detect any abnormalities.

Unlike a standard pelvic ultrasound, saline infusion sonography allows clinicians to see inside the uterus in much greater detail. The saline acts as a contrast agent, separating the walls of the uterine cavity and highlighting any structural irregularities that might otherwise remain hidden.

The procedure is typically performed using 3D ultrasound technology, which provides comprehensive three-dimensional images of the uterine cavity. This enhanced visualisation capability makes SIS particularly valuable for fertility assessments and pre-IVF evaluations.

Why Is SIS Important Before IVF Treatment?

The uterine cavity plays a crucial role in IVF success, as it must provide an optimal environment for embryo implantation and early pregnancy development. Research has demonstrated that obtaining an SIS before frozen embryo transfer cycles can be particularly helpful in detecting uterine abnormalities that may compromise treatment outcomes.

Intrauterine lesions and structural abnormalities can significantly impact the success of assisted conception procedures. Even minor irregularities in the endometrial cavity can create barriers to successful implantation, leading to failed IVF cycles or early pregnancy loss.

Many fertility specialists recommend SIS as part of comprehensive pre-IVF assessment, particularly if it has been more than 1-2 years since the last uterine evaluation. Early identification and correction of uterine abnormalities may substantially improve IVF success rates and reduce the emotional and financial burden of repeated failed cycles.

Conditions Detected by Saline Infusion Sonography

SIS is particularly effective at identifying various uterine conditions that can affect fertility and IVF outcomes. The enhanced visualisation provided by saline infusion allows for accurate diagnosis of both common and complex abnormalities.

• Endometrial polyps: Small growths on the uterine lining that can interfere with implantation
• Submucosal fibroids: Benign tumours that protrude into the uterine cavity
• Intrauterine adhesions: Scar tissue bands that can distort the uterine cavity
• Congenital uterine anomalies: Structural abnormalities present from birth, such as septate uterus
• Endometrial thickness irregularities: Variations in the uterine lining that may affect receptivity
• Cervical stenosis: Narrowing of the cervical canal that could complicate embryo transfer

The procedure can also evaluate the fallopian tubes when combined with additional techniques, providing a comprehensive assessment of reproductive anatomy. This information proves invaluable for treatment planning and optimising IVF protocols.

When Is SIS Recommended Before IVF?

Fertility specialists typically recommend SIS in various clinical scenarios before commencing IVF treatment. The timing and necessity of the procedure depend on individual circumstances and previous diagnostic findings.

Most commonly, SIS is advised when previous ultrasound scans have suggested possible uterine abnormalities, or when patients have experienced recurrent implantation failure or pregnancy loss. Women with a history of gynaecological procedures, such as D&C operations, may also benefit from SIS to assess for potential scarring or adhesions.

The procedure is particularly valuable for patients undergoing frozen embryo transfer cycles, as these treatments allow time for any necessary corrective procedures before embryo transfer. Some clinics now routinely include SIS as part of their comprehensive fertility assessment protocols to optimise treatment outcomes.

Additionally, SIS may be recommended if more than 1-2 years have elapsed since previous uterine evaluation, ensuring that any newly developed conditions are identified and addressed before treatment begins.

The SIS Procedure: What to Expect

The SIS procedure is typically performed as an outpatient appointment and takes approximately 15-30 minutes to complete. Understanding what to expect can help reduce anxiety and ensure optimal preparation for the examination.

The procedure is scheduled between day 6 and 11 of your menstrual cycle, counting the first day of menstrual bleeding as day 1. This timing ensures that the endometrium is thin enough for optimal visualisation whilst avoiding the risk of accidentally performing the procedure during early pregnancy.

During the examination, you’ll be positioned similarly to a routine gynaecological examination. A speculum is gently inserted to visualise the cervix, and a thin, flexible catheter is passed through the cervical opening into the uterine cavity. Sterile saline solution is then slowly infused whilst transvaginal ultrasound images are obtained.

Many patients experience mild cramping during the procedure, similar to menstrual discomfort. Your healthcare provider may recommend taking paracetamol or ibuprofen beforehand to minimise any discomfort. The procedure is generally well-tolerated, and most patients can resume normal activities immediately afterwards.

Preparing for Your SIS Appointment

Proper preparation helps ensure the procedure proceeds smoothly and provides optimal diagnostic information. Your healthcare team will provide specific instructions tailored to your individual circumstances.

Timing is crucial for SIS accuracy and safety. The procedure must be scheduled during the correct phase of your menstrual cycle to avoid pregnancy and ensure optimal visualisation. If you have irregular cycles or are unsure about timing, discuss this with your healthcare provider well in advance.

Some practitioners recommend taking over-the-counter pain relief approximately 30-60 minutes before your appointment to minimise cramping. If you have a history of severe period pain or anxiety about medical procedures, discuss pain management options with your healthcare team beforehand.

It’s advisable to wear comfortable, easily removable clothing and consider bringing a supportive friend or partner if this would help you feel more comfortable. Most patients find the procedure manageable and are reassured by understanding what to expect throughout the process.

Interpreting SIS Results

SIS results are typically available immediately after the procedure, as the images are reviewed in real-time during the examination. Your sonographer or consultant will explain the findings and discuss any implications for your fertility treatment plan.

Normal SIS results show a smooth, regular uterine cavity with appropriate endometrial thickness and no structural abnormalities. The cervical canal should appear patent, and the overall uterine shape should be consistent with normal anatomy.

If abnormalities are detected, your healthcare team will discuss the significance of these findings and potential treatment options. Some conditions, such as small polyps or minor adhesions, may require surgical correction before proceeding with IVF treatment. Others might be managed conservatively or may not significantly impact treatment success.

The detailed images obtained during SIS provide valuable information for treatment planning, allowing your fertility team to optimise embryo transfer techniques and timing based on your individual uterine anatomy.

Treatment Options Following SIS

When SIS identifies uterine abnormalities, various treatment options may be recommended before proceeding with IVF treatment. The approach depends on the specific condition identified and its potential impact on fertility outcomes.

Hysteroscopic procedures represent the most common treatment approach for intrauterine abnormalities. This minimally invasive surgical technique allows direct visualisation and treatment of conditions such as polyps, small fibroids, and adhesions. Most hysteroscopic procedures can be performed as day cases with minimal recovery time.

For more complex abnormalities, such as large fibroids or significant congenital anomalies, additional surgical procedures may be necessary. Your consultant will discuss the risks and benefits of various treatment options, considering factors such as your age, overall health, and fertility goals.

In some cases, minor abnormalities may not require treatment before IVF, and your fertility team may proceed with modified protocols to accommodate your individual circumstances. The decision-making process involves careful consideration of current evidence and your specific situation.

Risks and Limitations of SIS

SIS is considered a safe procedure with minimal risks when performed by experienced practitioners. Understanding potential complications helps patients make informed decisions about their care.

The most common side effects include mild cramping during and shortly after the procedure, similar to menstrual discomfort. Some patients may experience light spotting for 1-2 days following SIS, which is considered normal. Serious complications are extremely rare but may include infection or allergic reaction to the saline solution.

Certain conditions may limit the effectiveness of SIS or make the procedure more challenging to perform. Severe cervical stenosis may prevent catheter insertion, whilst active pelvic infection represents a contraindication to the procedure. Your healthcare provider will assess your suitability for SIS during the consultation process.

Whilst SIS provides excellent visualisation of the uterine cavity, it may not detect all abnormalities, particularly those located within the uterine wall or outside the endometrial cavity. Additional imaging or diagnostic procedures may sometimes be necessary for comprehensive assessment.

Alternatives to SIS

Several alternative diagnostic methods exist for evaluating the uterine cavity, each with distinct advantages and limitations. Understanding these options helps patients and healthcare providers select the most appropriate approach for individual circumstances.

Hysterosalpingography (HSG) represents a traditional method for assessing uterine cavity and fallopian tube patency using X-ray imaging with contrast dye. Whilst effective for detecting major abnormalities and tubal blockages, HSG involves radiation exposure and may be less comfortable than SIS.

Diagnostic hysteroscopy provides direct visualisation of the uterine cavity using a thin, lighted scope passed through the cervix. This procedure offers excellent diagnostic accuracy but requires more extensive preparation and may need to be performed under anaesthesia in some cases.

Standard transvaginal ultrasound can identify many uterine abnormalities but may miss subtle intrauterine lesions that become apparent with saline infusion. MRI scanning provides detailed images of uterine structure but is more expensive and may not be readily available for routine fertility assessments.

Cost Considerations and Insurance Coverage

The cost of SIS varies depending on the healthcare setting and geographic location. Understanding financial implications helps patients plan for fertility treatment expenses and make informed decisions about their care.

In the UK, SIS may be available through NHS fertility services as part of funded IVF treatment, though availability varies by clinical commissioning group and individual circumstances. Private fertility clinics typically offer SIS as part of comprehensive fertility assessment packages or as standalone procedures.

When considering the cost of SIS, it’s important to weigh this against the potential costs of failed IVF cycles due to undiagnosed uterine abnormalities. Early identification and treatment of intrauterine conditions may improve treatment success rates and reduce overall treatment costs.

Some private medical insurance policies may cover diagnostic procedures such as SIS when performed for medical indications. Patients should check with their insurance providers about coverage criteria and pre-authorisation requirements before scheduling the procedure.

How the London Pregnancy Clinic Can Help

The London Pregnancy Clinic offers comprehensive saline infusion sonography services using state-of-the-art 3D ultrasound technology. Our experienced sonographers and consultant specialists provide thorough evaluations to support your fertility journey and optimise treatment outcomes.

Our clinic utilises advanced imaging equipment to ensure optimal diagnostic accuracy and patient comfort during SIS procedures. The detailed 3D images obtained during your scan provide comprehensive information about uterine anatomy, helping to identify even subtle abnormalities that could impact fertility treatment success.

Following your SIS examination, our team provides detailed explanations of your results and discusses any implications for your fertility treatment plan. We work closely with fertility specialists to ensure seamless communication and coordinated care throughout your treatment journey.

Our commitment to patient-centred care includes flexible appointment scheduling and comprehensive support throughout the diagnostic process. We understand the emotional aspects of fertility treatment and strive to provide a comfortable, supportive environment for all our patients undergoing IVF-related assessments.

Final Thoughts

Saline infusion sonography represents a valuable diagnostic tool in modern fertility medicine, providing detailed assessment of the uterine cavity before IVF treatment. The procedure’s ability to identify conditions that could compromise treatment success makes it an important consideration for many patients embarking on assisted conception.

Whilst not every patient requires SIS before IVF, the procedure offers significant benefits for those with suspected uterine abnormalities or previous treatment failures. Early identification and treatment of intrauterine conditions can optimise treatment outcomes and reduce the emotional and financial burden of repeated unsuccessful cycles.

If you’re considering IVF treatment or have questions about whether SIS might benefit your specific circumstances, consult with experienced fertility specialists who can provide personalised recommendations based on your individual medical history and treatment goals. Taking a comprehensive approach to fertility assessment, including procedures such as SIS when indicated, represents an investment in optimising your chances of achieving a successful pregnancy through assisted reproductive treatment.

Sources

1. ROUTINE SALINE INFUSION SONOHYSTEROGRAPHY PRIOR TO ASSISTED CONCEPTION: A REVIEW OF OUR INITIAL EXPERIENCE – PMC
2. Role of saline infusion sonography in uterine evaluation before frozen embryo transfer cycle – PubMed
3. What to Know When Your Ob/Gyn Recommends Saline Infusion Sonography
4. FAQ’s : University College London Hospitals NHS Foundation Trust
5. Saline Infusion Sonohysterography (SIS) Fertility Scan in …
6. Saline Infusion Sonohysterography (SIS): Ultrasound of Uterus
7. Saline Infusion Sonogram & FemVue | UCSF Center for Reproductive Health
8. 3D Saline Infusion Sonography (3D SIS) | CRGH
9. Role of saline infusion sonography in uterine evaluation before frozen embryo transfer cycle – ScienceDirect
10. Do You Need a Saline Sonogram Before IVF? Here’s What It Reveals | American Surrogacy Blog
11. Saline Infused Sonography (SIS): Indications, Preparation and Outcome | Advanced OBGYN Institute
12. Saline Sonogram Fertility Test – What is does and how it works