What Is A Dating Scan?

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Key Takeaways:

  • A dating scan is a type of ultrasound scan that is used to determine the gestational age or estimated due date of a pregnant woman.
  • The purpose of a dating scan is to accurately date the pregnancy, confirm the fetal heartbeat, and identify any potential abnormalities.
  • The procedure of a dating scan involves preparing for the scan by drinking water, undergoing the scan which can be either abdominal or vaginal, reviewing the images, and receiving an estimated due date based on the measurements taken.
  • A dating scan is usually done between 8 and 14 weeks of pregnancy, and it is more accurate for women with regular 28-day cycles compared to those with longer or irregular cycles or those on contraception.
  • Additional information, such as the baby’s size and heartbeat, can be gained from the 12-week scan, and screening tests for Down’s syndrome may be offered.
  • While pregnancy scans can provide valuable information, they also have some potential disadvantages, such as anxiety and false positives, that should be considered.


When you’re pregnant and have more questions than answers, a dating scan could provide the information you need. It’s normal to feel apprehensive about a medical procedure, but understanding what a dating scan is and how it works can help alleviate some of those nerves. In this section, we’ll take a closer look at what a dating scan is and why it’s an important part of prenatal care.

What is a dating scan?

A dating scan is a medical procedure that utilizes ultrasound technology. It’s used to work out the gestational age of a developing fetus during early pregnancy. Images of the baby can help healthcare pros to estimate its due date with accuracy.

During a scan, healthcare pros will measure the size of the fetus. They’ll also evaluate the heart rate, for more precise estimation of when the baby will arrive. This scan is a routine part of prenatal care in many countries. It gives mums valuable info about their pregnancy early on.

It’s recommended that scans take place between 8-14 weeks of pregnancy. For regular 28-day menstrual cycles, 12 weeks is the most accurate prediction. Scans are less reliable for women with long/irregular cycles or using contraception.

Nuchal translucency screening tests during 12-week ultrasounds can produce false-positive rates. This can lead to unnecessary anxiety and interventions. A dating scan offers reassurance and a more reliable way to determine due date. Love may be blind, but a dating scan ensures your due date won’t be!

Purpose of a dating scan

A dating scan has a critical medical purpose during pregnancy. It estimates the due date of the baby accurately, usually carried out between 8-14 weeks. Healthcare professionals measure the fetus size and check the number of weeks of pregnancy. The scan can also detect abnormalities or complications which need medical intervention.

Furthermore, the scan offers information about the development of the fetus. It checks the number of fetuses, their position in the uterus, and any structural issues. This information is necessary for healthcare professionals to offer the best care. The purpose of a dating scan is more than just the due date. It is an essential tool in guaranteeing the well-being of both the mother and the baby throughout pregnancy.

Procedure of a dating scan

Being pregnant can be both an exciting and daunting experience for women. In this section, we will explore the procedure of a dating scan, which is one of the most common ultrasound examinations performed on pregnant women. We will take a closer look at the different aspects of the procedure, including:

  1. How to prepare for the scan
  2. The actual procedure
  3. Recommended full bladder for better images
  4. Potential need for a vaginal scan to obtain a clearer picture.
  5. Finally, we will also discuss the review of images and how the expected due date is determined.

Preparation for the scan

Proper prep is essential for precise results during a dating scan. It is advised that in the hour before the appointment, you should drink lots of water to have a full bladder. This makes it simpler for the sonographer to get clear images. Additionally, try not to go to the bathroom before the scan and put on loose clothes that allow easy access to your abdomen.

If you opted for a vaginal scan, make sure to empty your bladder beforehand and wear a skirt or dress instead of pants. Also, women who are 8-10 weeks pregnant should choose the transabdominal approach as it yields clearer images.

Also, inform your sonographer if you had prior surgeries or medical conditions that may impact the scan. Remember that the prep may differ depending on the instructions given by your healthcare provider or sonographer.

Having an accurately estimated due date is critical for monitoring fetal growth and development throughout pregnancy. Also, it can help decide appropriate care plans for both mother and baby. Unreliable estimated due dates can lead to unnecessary interventions such as induced labor or caesarean section deliveries.

A study by C. Song et al. found that correct preparation for a dating scan can enhance the accuracy of estimated due dates and lessen these risks. Thus, preparing properly for a dating scan is vital to ensure the best possible outcome for both mother and baby.

Procedure of the scan

A dating scan is a medical imaging test to figure out the gestational age and due date of a baby in the womb. It involves five steps:

  1. The patient lies down on the examining table.
  2. Gel is put on their abdomen.
  3. Sound waves are sent through the gel to the fetus.
  4. Measurements of fetal crown-rump length are taken and compared to charts.
  5. Images and measurements are reviewed by an obstetrician who will give an estimated due date.

Transvaginal ultrasounds may be used in some cases for better visualization. Overall, accurate scans early on are important for baby’s health and prenatal care.

Recommended full bladder for better images

A full bladder is advised for better visualization of the fetus during a dating scan. This pushes the uterus upwards, which helps get accurate measurements and determine gestational age and due date. However, not all women may find it comfortable to have a full bladder. Having a full bladder is still typically recommended for better images.

It is important to keep in mind that this varies depending on each pregnancy and the healthcare provider’s preference. Vaginal scans can be done instead of abdominal scans for those who find it uncomfortable. So, if you want a clear image during a dating scan, it is advised to have a full bladder.

Vaginal scan for better picture

For those wanting a more accurate image of their pregnancy, a vaginal scan may be suggested. Unlike traditional scans, which use ultrasound waves from the outside, a vaginal scan captures images from inside the uterus. This gives a clearer image and can be useful when the first scan didn’t show enough detail.

A vaginal scan may seem uncomfortable or invasive, however it is safe and painless. Most scans take just 15 minutes.

It is possible to get accurate results without a second scan after the first dating scan with regular menstrual cycles. But if you want extra reassurance or have had complications in past pregnancies, a vaginal scan may be an option.

It is a personal preference and depends on individual circumstances. Speak with your healthcare provider to help you decide.

Finally, get a due date you can rely on – unlike that ex who said they’d call back!

Review of images and expected due date

A dating scan is essential for reviewing images and determining due dates. The healthcare provider will examine the images to make sure measurements and features are consistent with the gestational age and fetus development.

Using a table can organize the data. It could have columns for important info such as crown-rump length measurement, fetal heartbeat, due date based on measurements, and any notes or comments from the healthcare provider.

It’s significant to know that the date may change during pregnancy because of subsequent scans or fetal growth patterns. Some women don’t have regular menstrual cycles which might affect the accuracy of dating scans. That’s why more scans might be needed to reevaluate due dates.

Accurate dating helps identify complications early and provide appropriate prenatal care.

Want to know your due date and have an ultrasound image of your baby? Schedule a dating scan!

When is a dating scan usually done?

A dating scan is a common procedure in prenatal care that uses ultrasound to estimate a baby’s due date. In this section, we’ll discuss when a dating scan is usually done and why it’s important for expecting mothers to have an accurate estimated due date. We’ll also touch on the accuracy of dating scans for women with regular 28-day cycles versus those with long or irregular cycles or those on contraception.

Accurate dating scans for women with regular 28-day cycles

Dating scans, using ultrasound tech, are super important for doctors. They estimate a pregnant woman’s due date. Regular 28-day menstrual cycles? These scans show an accurate gestational age and expected delivery date. During the scan, a sonographer takes images of the uterus and fetus. They measure the fetus’ size. This is done with crown-rump length and biparietal diameter. Then they compare it to growth charts. This shows how many weeks pregnant the woman is.

But, dating scans may not be as reliable for women with longer or irregular cycles. Or, those using hormonal contraception like birth control pills or implants. In such cases, doctors may need other methods. Such as early pregnancy blood tests or multiple ultrasound scans. This helps determine gestational age and due dates more accurately.

Knowing the estimated due date is really important. It helps plan prenatal care and detect potential problems early in pregnancy. Pregnant women should discuss with their healthcare providers when to schedule a dating scan. This depends on their medical history and cycle regularity. Relying on medical professionals may be the best option. Crystal ball predictions won’t work here!

Inaccurate dating scans for women with long or irregular cycles or those on contraception

Dating scans are a handy way to guess a pregnant woman’s due date. But, these scans may not be right for women with long or unusual menstrual cycles or those who take birth control. Studies show these things can cause incorrect results from dating scans. In these cases, doctors may need to ask more questions to learn the woman’s cycle length or what kind of birth control is used.

For women with cycles that are longer or more unpredictable than 28 days, it can be hard to tell how old the baby is. This is because scans usually assume ovulation happens 14 days after the last period. But, changes in cycle length and regularity can affect this. Birth control that stops ovulation can also complicate a dating scan.

It’s important to get the right due date because medical procedures like inducing labor and having a c-section are based on it. If the due date isn’t accurate, more scans may be needed during pregnancy to check the baby’s age and growth.

Overall, accurate scans are important for a healthy pregnancy. Women with long or irregular menstrual cycles or taking birth control need more information for an accurate age estimate.

Importance of an accurate estimated due date

Accurate estimated due dates are essential for proper fetal growth and the birth of a healthy baby. Dating scans, which provide a reliable estimate based on the size of the fetus, are a great tool.

Having accurate due dates allows health professionals to closely monitor fetal growth. This helps them plan prenatal care and determine if the baby is premature or overdue. Also, dating scans can identify multiple or ectopic pregnancies.

Regular cycles provide more reliable estimates than irregular cycles or women using contraceptives. If an inaccurate estimated due date was obtained, a follow-up scan can be scheduled.

Maintaining healthy habits during pregnancy can improve the accuracy of estimated due dates. For example, quitting smoking and being open about past medical conditions.

Overall, obtaining an accurate estimated due date is very important for mother and baby throughout pregnancy and delivery.

12 week scan and potential abnormalities

Did you know that a 12-week scan can identify potential abnormalities in your developing baby? In this section, we’ll take a closer look at what the scan can tell us about the baby’s size and heartbeat, as well as the screening tests used to detect Down’s syndrome. Additionally, we’ll explore the disadvantages of pregnancy scans to help you make an informed decision about whether or not to have this important test.

Baby’s size and heartbeat

A table with the right columns gives a look at the baby’s measurements during the scan. This includes measurements of the crown-rump length (CRL) to work out gestational age. A healthy baby should measure 45mm – 84mm in CRL. Its heartbeat should be there too, showing all is well.

But, if the woman has irregular menstrual cycles or was conceived through IVF or fertility drugs, the measurements may not be so accurate.

It’s interesting to think about how these scans began. They came into use in the 1980s due to improved ultrasound technology. This gave medics more knowledge on fetal growth and prenatal diagnosis. Nowadays, they are still useful for docs and parents-to-be.

Screening tests for Down’s syndrome

During pregnancy, screening tests for Down’s syndrome are conducted to identify any abnormalities in the growing fetus. These tests can provide a probability of the condition, but not an exact answer. Three common screening tests are the NT scan, the NIPT, and the Combined Test.

The NT scan measures fluid at the back of the baby’s neck. Higher fluid levels can suggest Down’s syndrome. This test is 70-90% accurate. The NIPT is a blood test that checks for chromosome changes. It can detect more than 99% of cases but can have false positives & negatives. The Combined Test is a mix of the NT scan and blood tests. It can be 75-85% accurate in detecting Down’s syndrome.

If screening test results are high for Down’s, further testing may be offered. This includes CVS or amniocentesis. These tests come with risks & limitations, so it is important to consult healthcare professionals. One mother shared her experience, which included results suggesting Down’s, but later having a healthy baby without any abnormalities. She stressed the importance of being informed about the risks & limitations of screening tests, not letting the results cause undue stress & anxiety.

In conclusion, while screening tests for Down’s are important, it’s essential to weigh the pros & cons before making decisions. Additionally, while pregnancy scans may reveal potential issues, the downside is having to stare at your bladder for an hour beforehand.

Disadvantages of pregnancy scans

Pregnancy scans are a valuable tool for medical pros. They accurately track fetal development. But, there are some drawbacks too.

  • One is that the scan exposes the fetus to low levels of ultrasound energy. This could be harmful. Over-reliance can lead to false results or missed abnormalities. The cost may not be covered by insurance.
  • Issues can arise if the image is unclear or misinterpreted. The fetus might be in an awkward position or the machine may be poor quality. Plus, ultrasound use has made other methods of monitoring less important.
  • Sometimes parents get anxious or stressed after getting scan results. That can be hard to deal with.

Despite the negatives, pregnancy scans are still essential. It’s important for parents to talk to their healthcare provider about any worries.


We wrap up this article with one conclusion: the dating scan is major for prenatal care. It tells us the due date, and can spot possible problems. Plus, it’s a special moment for would-be parents to bond with their unborn child.

But beware: the dating scan isn’t a diagnostic test. If any issues come up, you’ll need more tests.

All in all, the dating scan is important. It helps make sure mom and baby stay healthy. So go to all doctor appointments and follow any testing or treatments they suggest.

Five Facts About What Is A Dating Scan:

  • ✅ A dating scan is an ultrasound scan done during pregnancy to estimate the baby’s due date. (Source: babycentre.co.uk)
  • ✅ Dating scans are generally accurate within 3-5 days. (Source: babycentre.co.uk)
  • ✅ The scan measures the baby’s size, heartbeat, and potential abnormalities at around 12 weeks. (Source: babycentre.co.uk)
  • ✅ The scan takes around 30 minutes and requires water-soluble gel applied to the tummy. (Source: womensimaging.net.au)
  • ✅ A vaginal scan may also be performed for a better picture of the developing baby. (Source: babycentre.co.uk)

FAQs about What Is A Dating Scan?

What is a dating scan?

A dating scan is an ultrasound scan done between 8 and 14 weeks of pregnancy to estimate the baby’s due date and check for any abnormalities. It measures the baby’s size to help the doctor estimate how long the pregnancy has been.

What does a dating scan involve?

A dating ultrasound scan involves a gel being applied to the abdomen and a probe being moved over the skin to create images of the baby. The scan takes about 30 minutes. A vaginal scan may also be performed for a better picture of the developing baby.

Can I bring someone with me to the scan?

Only one person is allowed for the scan, and children are normally not allowed. Recording devices are not allowed.

What information is required before a dating scan?

The patient fills out a form about the last menstrual cycle and relevant details. A full bladder is recommended for better images of the uterus.

What is the expected due date given during a dating scan?

The expected due date is given on the day of the scan. An online access card is provided to view the images.

What are the advantages and disadvantages of pregnancy scans?

The advantages of pregnancy scans include early detection of abnormalities and reassurance of a healthy pregnancy. Disadvantages are rare but can include false positives or negatives, anxiety, and unnecessary interventions.

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