Dating Scan

This is an ultrasound scan that is performed early in the pregnancy.

Measurements are taken such that the dates of the pregnancy can be confirmed or determined. Other information obtained includes whether the pregnancy is in the uterus or outside the uterus (an ectopic pregnancy), how many embryos there are, and whether there are any complications surrounding the pregnancy at this early stage. The ovaries and kidneys are also examined.

What to expect on the day?

The scan takes 30 minutes to perform.

When you arrive for your scan you will be asked to fill out a form about when your last menstrual cycle took place (if known) and some other details relevant to the scan.

You will be called by the sonographer who will take you to the scanning room.

You will be asked to lie on the table and to expose your tummy and a towel will be tucked into your pants to limit spread of the gel onto your clothes. The gel that we use is water-soluble so it does not stain your clothes. It can just be a bit sticky!

Clear gel is applied to your tummy and the sonographer moves the probe over your tummy recording images.

Please come with a full bladder which will make it easier to obtain images of the uterus.

Usually a vaginal scan is also performed. This gives us a much better picture of your developing baby. You will be able to see for yourself on our plasma screen monitors! After emptying your bladder and wearing a gown you will lie on the bed and a special probe is positioned in your vagina. This has a sterile disposable cover. During this examination the vaginal probe is moved with varying pressure at different angles to obtain images of the uterus and ovaries.

The sonographer will leave the room after the scan to review the images and to discuss them with the Radiologist.

You will be given your expected due date on the day.

You will receive a text message within 24 hours of your appointment with a link to access your images through our online portal.  Your images will be available to view within 3 days of your appointment.

Risks

Ultrasound is safe to use throughout your pregnancy.

If you are allergic to latex prior to the vaginal scan or you don’t know, then a latex-free cover will be used on the probe.

Occasionally there is some discomfort from probe pressure on a full bladder or from the vaginal probe manipulation. If this is extremely painful please let us know.

Benefits

You will be able to get your expected due date of your baby on the day.

You will be made aware if there is anything of concern on the day.

If you have any questions you will be able to ask our on-site radiologist.

Common questions about this scan

What is an Ultrasound scan?

An ultrasound scan uses high-frequency sound waves to create images of the inside of the body. Sound waves are used instead of radiation which makes them safe.

Will my baby be ok during the scan?

Ultrasound can be safely used during pregnancy. Having a vaginal scan does not impact on your baby’s wellbeing.

Do I need to do anything before I have this scan?

You will need to arrive with a full bladder before you have your scan. A full bladder allows us to see your uterus and ovaries more clearly. We normally recommend that you have 2 glasses of water a half hour before you arrive for your scan.

How long will the scan take?

The scan will take up to 30 minutes on the day.

What happens on the day?

You will lie down with your tummy exposed and a towel tucked into your pants.

The sonographer will place gel on your tummy and which allows the probe to move more freely over your tummy. Pressure will be applied but this is usually not painful to you or harmful to the baby. We like you to have a full bladder as it makes it easier for us to see your uterus and ovaries from across your tummy.

We also have a look at your kidneys as occasionally the baby can lie on your ureter (which drains the urine from your kidneys) causing you some problems later in the pregnancy. So we like to know your kidneys are normal at the start of your pregnancy so if a problem arises later we know it is your baby causing the issue!

After we scan across your tummy we will then send you to empty your bladder. We like to do a vaginal scan as this gives us better visualization of your developing baby and where the pregnancy is developing in your uterus. You will be able to see the difference in the clarity of the scan across your tummy compared to a vaginal scan on our wall-mounted monitors.

After your scan the sonographer will leave the room to discuss the images with the radiologist or obstetrician who may require more images to be performed. This is normal practice and nothing to be alarmed about.

Other obstetric scans

Once you have been given your expected due date at your dating scan, the next scan will be the 12-14 week scan. This  scan will allow you to see your baby’s developing organs. At the 20 week scan your baby’s organs will be fully formed and you will get to see just how big they have grown between scans!