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13 Week Ultrasound

The 13 week ultrasound examination is often the official first trimester ultrasound offered by your hospital, unless there are extraneous circumstances that require an earlier ultrasound. This is otherwise called the dating scan because it’s used to date the pregnancy in terms of conception and due date. It will also make sure the pregnancy is viable and progressing as it should.

The majority of ultrasounds at 13 weeks can be performed through the abdomen as the baby is large enough to be picked up through the stomach tissues. This consists of a probe that uses sound waves being moved over your stomach to see a picture of your baby projected on a computer screen.

How do 13 week ultrasounds work?

The 13 week scan will be completed with an ultrasound probe being pushed gently into your stomach until your sonographer finds your baby. They will put a small amount of water-based gel onto your stomach before the probe to improve the connection and ensure the images are as clear as possible.

The probe uses electrical currents to create sound waves that penetrate your skin when the probe is placed on your stomach. The sound waves head straight into the skin and don’t stop until they hit something. Once they find an object they bounce back to the probe, which converts them back into electrical currents.

These electrical currents will be in a pattern which is sent to the computer to display on the computer screen. This is done within seconds to give you real-time video footage of your baby moving around in your stomach. Sound waves are considered safe to use near unborn children and parents, so there’s no risk associated with your ultrasound.

Why might you need a 13 week ultrasound?

Most doctors offer the first trimester ultrasound between 11 and 13 weeks, and this is so that they can track the pregnancy and make sure your baby is growing at the correct rate for which it should be. This official ultrasound is considered a risk assessment for your baby, so it’s a necessary appointment for you to attend.

There are several reasons why you’ll need a 13 week ultrasound, including:

      • To make sure your baby is growing well

      • To confirm your due date

      • To make sure there are no structural abnormalities

      • To check your uterus and ovaries to make sure they’re responding well to the pregnancy

      • To confirm the baby and placenta are growing at the correct rate for your due date

      • To find out where the placenta is lying

      • To determine where the umbilical cord is and if it’s likely to become an issue in later pregnancy

      • To measure the amount of fluid around the baby and make sure there’s enough

The 13 week ultrasound is an excellent way of putting your mind at ease by making sure everything is progressing as planned with your pregnancy. It might also be your first opportunity to see your baby.

How to prepare for your 13 week ultrasound

When you get the letter through for your appointment, it should detail any necessary measures you need to take to prepare for your 13 week ultrasound. Some hospitals require no preparation while others ask you to avoid foods before the scan.

A common method of preparing for the 13 week scan is to drink a litre of water before your appointment. This makes sure your bladder is full for the duration of your appointment, which can make it easier for the sonographer to see your baby. They might ask you to empty your bladder halfway through your appointment if your baby is in a position to be seen without it.

The majority of hospitals will allow you to bring one support person with you into the scanning room. However, you are usually deterred from bringing multiple people or children with you as the sonographer needs quiet to be able to concentrate on your baby.

Where possible, wearing comfortable clothing is advised when arriving at your 13 week scan. This is so you can remain comfortable throughout the ultrasound and so you can pull the waistband down for your sonographer to have full access to your stomach. You’ll likely have remnants of gel on your stomach after the scan, too, so wearing loose clothing can prevent them from running.

What to expect from your 13 week ultrasound

During the scan

By 13 weeks, your baby is often large enough to be seen through a transabdominal scan so you don’t have to worry about a transvaginal ultrasound. However, in rare cases where your baby cannot be seen through your stomach, the latter will be offered.

When entering the ultrasound room, you’ll be greeted by your sonographer and asked to lie on the cushioned table. This will either be slightly inclined or lying flat. Your support person will be able to sit on a chair next to you if you have brought someone with you.

You’ll be asked to pull your waistband down a little to give the sonographer better access to your lower abdomen. Your top may also need to be slightly raised. You will be given a paper towel to tuck into your waistband to protect your clothing from getting covered in gel.

Once you’re ready for the examination to begin, the sonographer will put a little water-based gel on your stomach to help the probe glide over the skin easier. It will also help the probe make better connection with your skin to keep the images of your baby as clear as possible.

The probe will then be placed on your lower stomach. Your sonographer might wiggle it and push it around on your belly while they’re looking for the baby, which can be a little uncomfortable for the patient. This shouldn’t cause discomfort though, so make sure you tell your ultrasound technician if you’re in pain.

The sonographer will take images and measurements of your baby during the scan, and they’ll often talk you through the basics of what they’re seeing. They won’t be able to answer most questions as these will need to wait until your doctor has reviewed the scan results.

Most ultrasounds take between 15 and 30 minutes, but some might take longer if your baby is in an unfavourable position. Your sonographer might ask you to walk around to help the baby get into a better position before continuing the scan.

After the scan

Once the scan has been concluded and your ultrasound technician is happy with all the information they’ve captured, they’ll invite you to stand from the table and wipe the excess gel from your stomach with a paper towel. After the gel has been removed you’ll be able to fix your clothing comfortably.

You’ll likely then need to wait for your doctor to call you into their office to discuss the findings. Most sonographers won’t talk you through what they’ve found on the ultrasound, but you won’t have to wait too long to get your results.

After you’ve gone through the findings and had all your questions answered by your doctor, you should be able to leave the hospital and resume everyday activities.

What are the benefits of 13 week ultrasounds?

The 13 week pregnancy scan is performed as a risk assessment to make sure your baby is growing as they should and to help you determine the date of conception and due date. They’re often the first time parents are able to see their babies, too.

  • The dating scan can be used to determine how many weeks pregnant you are and your estimated due date

  • You’ll be able to determine whether you’re having one baby or multiple

  • The ultrasound technician can take measurements of your baby to make sure they’re growing at the correct pace

  • Certain genetic conditions can be seen as early as 10 weeks, so the dating scan can show doctors whether there’s cause for concern

  • An ultrasound is a non-invasive procedure that causes no harm to parent or baby


What can I expect at my 13 week ultrasound?

During the scan, your baby’s growth will be measured and any risks will be assessed. This includes checking their heartbeat, the length of their limbs, and other essential developmental milestones. You should be able to hear your baby’s heartbeat and see them on the computer screen. The scan will often last between 15 and 20 minutes, but it can take longer if your baby isn’t in the best position to be seen through the scan.

Can you tell gender at 13 week ultrasound?

While some medical professionals state that the gender can often be told at 13 weeks, most hospitals have a policy that the gender scan won’t be offered until nearer 20 weeks. The longer you wait to determine the gender, the more accurate the results will be. So, your answer at 13 weeks might be inaccurate and lead to false results.

Can you see abnormalities at 13 weeks?

The 13 week scan can identify a number of non-chromosomal foetal abnormalities, although additional scans and tests will be necessary in the second and third trimesters to learn more about the severity of these.