What is a Saline Sonogram (SHG)? Procedure Guide, FAQs & More

Before you begin fertility treatment, your doctor needs to uncover any potential roadblocks. One of the ways they do this is by performing a diagnostic cycle, which includes a short test called a saline sonogram (also known as a sonohysterogram, or SHG). 

In this article:

• What is a saline sonohysterogram (SHG)?
• What to Expect at Your SHG Test
• What happens before an SHG?
• What happens during an SHG?
• What happens after an SHG?
• What are the risks of a sonohysterogram?
• Saline Sonogram vs HSG
• Will I have to repeat my SHG or HSG?
• Saline Sonohysterogram FAQs
• Is a sonohysterogram (SHG) painful?

What is a saline sonogram (SHG)?

A saline sonogram (also referred to as a sonohysterogram, saline ultrasound, saline infusion sonohysterogram, SIS, or SHG) is an important fertility test performed during the diagnostic process to help ensure there are no physical barriers to successful conception. 

Between days 5 to 9 of your menstrual cycle, your doctor will perform an SHG to carefully evaluate the shape of the uterine cavity and look for any fibroids, polyps, scar tissue, or other abnormalities that should be resolved prior to beginning fertility treatment.

Completing diagnostic tests like an SHG will give you the best chance of a healthy pregnancy.

As a medical assistant at Illume Fertility, my role includes helping our doctors perform procedures and diagnostic tests - such as sonohysterograms. In this guide, we will discuss what you can expect from an SHG test and answer common questions about the procedure to help you feel more at ease. 

What to Expect at Your SHG Test

During the diagnostic testing process, you will be given detailed instructions at each step, and will always be able to ask your nurse any questions you may have along the way.

However, we know it can feel overwhelming trying to keep track of what's next. With that in mind, let's walk through what to expect before, during, and after your sonohysterogram (SHG) to help you feel more prepared.

What happens before an SHG?

Your nurse or doctor will discuss the timing of your sonohysterogram with you to ensure it is performed at the proper time during your cycle. However, you should always contact your Care Team if you are still having a full flow (bleeding, not spotting) before your SHG. 

Here's what to expect:

• You'll be able to eat, drink and take any medications as you normally would (unless instructed otherwise).
• Wear comfortable clothes so that it’s easy to change into a gown if needed. 
• We recommend you take Tylenol or ibuprofen around one hour prior to your scheduled appointment. This will help reduce any potential discomfort you may feel during the procedure (i.e. cramping).
• If you are feeling extra anxious about your SHG, don't hesitate to tell your team! They can prescribe Valium to help you feel more relaxed. We all want you to be as comfortable as possible throughout the process.
• When you arrive at the office, you may be asked for a urine sample.
• You will review and sign a consent form for the procedure.
• A medical assistant will provide further instructions and help you get settled in the room.

What happens during an SHG?

During your sonohysterogram, you can expect to have a provider (typically, this will be your primary doctor) and a medical assistant in the room. If there happens to be a medical student or resident shadowing our team on the day of your SHG, you might be asked if you are comfortable having them in the room as well - which is completely up to you.

Reminder: If you are feeling anxious or uncomfortable at any point, always let your doctor know. They will do everything they can to help you feel more relaxed. 

Here's what to expect:

• The sonohysterogram itself usually takes around 15 minutes to complete.
• A small catheter will be placed inside your uterus.
• You will be fully awake and lying on your back with your knees bent. A slim wand called an ultrasound transducer will be gently inserted into your vagina. This slim wand will covered with a disposable protective sheath and coated with a special gel.
• Sterile saline (water) is then gently infused into your uterus through the catheter to provide a clear visualization of the uterine cavity.
• You can expect some cramping and mild discomfort as the saline enters your uterus.
• Your doctor will carefully examine your uterus via ultrasound to see if any polyps, fibroids, scar tissue, or other abnormalities are present.
• Ultrasound images (including 3D images) of the uterus will be taken in real time.
• Your doctor will review those images with you as soon as the test is completed.
  

What happens after an SHG?

After your SHG has been completed, a sanitary pad will be provided to capture any residual saline as it leaves the uterus. Fluid leakage is expected, so don't be alarmed if you see this.

Unless instructed otherwise, you will be able to continue on with your normal daily activities.

If you have any questions while you are still at the office, don't hesitate to ask your doctor or medical assistant. If any concerns arise after leaving the office, always feel free to contact your Care Team.

What are the risks of a sonohysterogram?

A sonohysterogram is low-risk and has very few, mild side effects. There’s a very slight chance of infection, but your provider will take steps to prevent this.

You may feel uncomfortable at points during the procedure, but taking over-the-counter pain medication (such as Tylenol or ibuprofen) one hour prior to your test can help.

If you notice any of these symptoms, let your Care Team know right away:

• Fever
• Intense pain
• Changes in vaginal discharge
• Bleeding after the test

Fertility 101 Guide

Explore how the personalized care Illume Fertility offers can help you achieve your goals, learn about each step of the process, meet our fertility doctors, view treatment options, and more.

Saline Sonogram vs HSG

Another test performed during the diagnostic process is called a hysterosalpingogram (HSG). The two procedures have similar names and common goals, but both are usually necessary for a complete fertility evaluation.

With that in mind, you may be wondering: how does an SHG differ from an HSG?

While the saline sonogram (SHG) is performed via transvaginal ultrasound, using sterile saline water to view the inside of the uterus, a hysterosalpingogram (HSG) involves the use of an X-ray to evaluate the anatomy of both the uterus and the fallopian tubes.

An HSG also uses a firmer catheter with a balloon tip in order to introduce iodine-based dye into the uterus, which can make the procedure more uncomfortable than an SHG.

Will I have to repeat my SHG or HSG? 

An hysterosalpingogram (HSG) is typically performed only once and is unlikely to be repeated.

A saline sonogram (SHG) must be repeated every six months, since polyps, fibroids, and other uterine abnormalities can develop. Both procedures are a part of our initial fertility evaluation here at Illume Fertility, as they help to determine the best next steps for each patient.

Saline Sonogram FAQs

If you have any lingering concerns before your appointment, keep reading to review some commonly asked questions about the saline sonohysterogram (SHG) test. 

How long does an SHG take?

The length of each sonohysterogram varies slightly, but you can expect the test itself to last between 15-20 minutes on average.

When should a sonohysterogram be performed?

The optimal time for a sonohysterogram is after your period has ended, but before you ovulate (usually around days 5 to 9 of your cycle). Why? This is when the lining of your uterus is at its thinnest, allowing your doctor to visualize the uterine cavity most clearly.

Is a sonohysterogram (SHG) painful?

You may feel some cramping or mild discomfort at times during your SHG, but for the most part, you should expect a quick, fairly painless experience. 

What is the difference between a sonohysterogram and hysteroscopy?

While a hysteroscopy and a sonohysterogram both allow your doctor to see inside your uterus, a sonohysterogram is less expensive, less invasive and faster than a hysteroscopy. The only downside to sonohysterography is it can only be used for diagnosis. Hysteroscopy allows your provider to remove any polyps, fibroids or scar tissue at the same time if needed.

How does a sonohysterogram actually work?

As the sterile saline is gently pushed through the catheter and into your uterus, the ultrasound wand sends sound waves through the gel and into your body. The echoes from those sound waves create a moving image of the inside of your uterus that your doctor then evaluates in real time. 

Why is an SHG necessary for fertility patients?

Saline solution expands the uterus and outlines the uterine cavity, which allows for a more detailed evaluation than a conventional ultrasound. Your doctor is then able to assess the uterus to ensure it is a healthy environment ready for an embryo to implant and develop in. 

Who else should get a sonohysterogram? 

A sonohysterogram can be a helpful tool for those who aren't trying to conceive as well. By evaluating the shape and structure of your uterus, your doctor may be able to pinpoint what is causing symptoms like pelvic pain and unexplained bleeding.

Your provider may recommend a sonohysterogram if:

1. Your menstrual periods are unusually heavy or prolonged.
2. You are having unexpected vaginal bleeding between your regular periods.
3. You have persistent, unresolved pelvic pain.

Getting a more comprehensive view of your uterine cavity helps your doctor establish an accurate diagnosis, keep tabs on any abnormal growths or possible issues, and assess whether surgical interventions will be necessary to resolve them. 

Fertility Testing is Essential to Your Success

While it can feel daunting to face a calendar full of appointments and learn about the many different tests involved in preparing for fertility treatment, remember the reason why you are choosing to put in all this effort: to give yourself the best possible chance at success.

If you have any questions not answered in this SHG guide, don't hesitate to reach out and ask your Care Team - they will always be happy to provide answers and reassurance.

We wish you all the best on your journey!