12-Week Ultrasound Scan: The Best Guide for Beginners

The ability to reproduce and give life to a new being is the greatest gift humankind has ever received.

A 12-week ultrasound scan or the scan done in the first trimester of the pregnancy is essential.

Pregnancy leads to a complete change in the female body and is challenging.

With every day that passes by, the body is subjected to change to accommodate the growing fetus and meet all its needs.

But the most crucial part during these 9 months of gestation is taking appropriate care and maintaining a thorough record of the growing fetus and the changes taking place in the woman’s body.

And with ever-advancing technology, healthcare has seen tremendous growth in the biotechnical field that has proved to help reach a diagnosis.

One of the most common screening tests used in scanning and documenting the growth and development of the baby is Ultrasound.

1. What Is an Ultrasound Scan?

Ultrasound is one of the most commonly used diagnostic tests which works on the principle of sound waves.

Ultrasound is a non-invasive screening test that generates images of the body’s internal structures.

The ultrasound machine generates high-frequency sound waves that are ultrasonic waves that are invisible to the human eyes. When reflected and refracted from a particular organ, these waves form an image.

Being a non-invasive test, an ultrasound scan is the most widely used scan to determine the developing baby’s growth.

12 week ultrasound
Photo by Volodymyr Hryshchenko on Unsplash Copyrights 2022

2. When to Get a 12-Week Ultrasound Scan Done?

Usually, the scan is done with the consultation of the doctor. Earlier, the scan was preferably done in 12 or 16 weeks.

But now it is done as early as in the 4th or 6th week. This scan is also used to confirm the pregnancies.

The 12-week ultrasound scan is usually carried out as a routine test in all three trimesters of the pregnancy.

The best way to determine when to carry out the scan is by the doctor’s advice.

3. Is It Necessary to Get the 12-week Scan Done?

One might feel that getting a scan done every month must be a trying job and unnecessary. Still, according to the Fetal Medicine Foundation, scanning plays a vital role in the risk assessment of the developing baby.

The 12-week ultrasound scan is important because the chances of miscarriage are increased in the first trimester of the pregnancy; thus, with the scan, the risk factors can be identified and acted upon immediately.

The scan as a routine test is crucial and should not be neglected.

4. Importance of a 12-Week Ultrasound Scan

The 12-week ultrasound scan helps the doctor visualize the organs and various other structures of the growing fetus and carry out the risk assessment.

It is common for the growing fetus to develop various abnormalities that may lead to the maldevelopment of the baby.

It may also lead to growth retardation, Down syndrome, trisomy, and other significant abnormalities that require quick intervention.

The 12-week ultrasound scan helps find out various abnormalities like:

4.1. Chromosomal Anomalies

Chromosomal abnormalities arise due to the presence of an extra pair of chromosomes or the absence of the required number of chromosomes.

In case there is the presence of chromosome abnormalities, specific development changes in the body that are not normal can easily be seen on the screen by a trained doctor and assistant.

The most prevalent chromosomal disorders are:

  1. Down’s syndrome
  2. Edward’s syndrome
  3. Triple X syndrome
  4. Turner’s syndrome
12 week ultrasound
Image by Gerd Altmann from Pixabay Copyrights 2019

4.1.1. Down Syndrome

Down’s syndrome is the most prevalent one and is caused due to the presence of extra genetic material at the 21 chromosome number.

To determine the presence of Down’s syndrome, the scan plays an important role.

The scan specially designed for checking this and other related pathologies is the nuchal translucency.

Nuchal Translucency

The nuchal translucency scan is usually carried out at the 12-week scan. When the patient agrees to go for this scan, the doctor checks the fluid-filled space present at the back of the baby’s neck.

If the baby has Down’s syndrome, there will be an increase in the thickness of the skin fold present at the neck of the baby.

Also, the nasal bone appears smaller than usual, and there is marked dilatation of the brain’s ventricles. The subsequent measurement is very crucial and should be done.

4.1.2. Edward Syndrome

Trisomy 18, also known as Edward syndrome, is the presence of the extra chromosome at the 18 number. In simple words, there is a duplicate of 18 number chromosomes.

This condition is rare but is very serious and determines how long a baby survives.

Diagnostic test like the ultrasound screening test helps detect this abnormality at an early stage and plans for further interventions.

4.1.3. Triple X Syndrome

As the name suggests, it is a chromosomal abnormality with an extra number of X chromosomes in females.

Usually, normal females have a single pair of X chromosomes. Still, in triple X syndrome1, the female child receives an extra X chromosome from the parent, and the condition has a ratio of 1:1000.

4.1.4. Turner Syndrome

In Turner’s syndrome, the females are the only ones affected as there is the absence of an X chromosome. In normal females, there is a pair of XX chromosomes that determines the sex of the baby.

In total, there are 46 chromosomes 2present in 23 pairs. Normal females have 46 XX and females with Turner syndrome have 45 X, which means there is a lack of one X chromosome.

4.2. Genetic Disorders

12 week ultrasound
Image by Mahmoud Ahmed from Pixabay Copyrights 2020

The scan helps the healthcare professional visualize the baby’s organs, the presence, and the position of the umbilical cord on the screen.

Also, the baby’s development is recorded in subsequent scans. As genetic conditions are prevalent to occur while the baby is in the womb, all these conditions are usually inherited and have a marked effect on the baby’s quality of life.

These diseases involve multiple organs and have thus multisystem disorders.

The most common ones are:

  1. Ankylosing Spondylitis
  2. Marfan syndrome
  3. Fragile X syndrome
  4. Dwarfism
  5. Sickle cell anemia
  6. Kyphoscoliosis
  7. Porphyria
  8. Hemophilia

A genetic disorder is a broad term, and many conditions may overlap in other categories, thus making doctors the best people to classify them.

4.3. Number of Babies

The 12-week ultrasound scan could be the first ultrasound 3that the woman must be undergoing.

By the 12th week, the baby has developed all the organs that are required, including the heart, liver, kidney, lungs, stomach, intestine, and bones, to name a few.

Thus, the parents-to-be can now listen to the baby’s heartbeat for the first time, which is usually twice the normal adult heart rate. The limbs of the baby are almost like a small bud and have just sprouted out.

Also, the most surprising thing that can be encountered during this scan is finding out the number of babies that are growing. The twin pregnancy is usually confirmed by the 12-week scan.

5. What to Expect on the Day of Ultrasound?

The date of the scan is usually predetermined, and a timetable is handed over to the patient.

In the case of a 12-week ultrasound, it could be the first time so ask the doctor regarding the date. Pregnant females are usually advised to come with a full bladder as the sound waves can quickly propagate through the liquid medium and thus help form a clear image.

Along with the scan, other combined tests like the blood pressure, estimation of the plasma protein, blood tests for blood grouping, and finding out the Rh factor are also done. You may also be asked to change into the gown if required and made to lie on the examination table.

After this, the healthcare practitioner exposes the area, usually the abdomen and the pelvis, to carry out the examination.

A clear gel is applied to the area to be examined and the head of the probe. This gel helps transfer the sound waves into the desired area without causing their dispersion.

The scan may be carried out for about 30 to 45 minutes.

12 week ultrasound
Image by MedicalPrudens from Pixabay copyrights 2014

After the doctor has got good imaging, the area is wiped out with cotton, and the female can now change into her regular clothes. As the gel is a bit sticky, an unusual feeling of stickiness around the abdomen is normal.

Also, screening for other health conditions like gestational diabetes4, thyroid, iodine deficiency, and anemia is done.

If the mother is at a greater risk of developing structural abnormalities or other chromosomal abnormalities, she is asked to carry out further tests.

Also, the scan helps determine the baby’s gestational age along with the estimated date of the delivery.

6. Takeaway

The 12-week ultrasound scan is usually done in the first trimester of the pregnancy. There are some things to remember:

  • Make sure you have made an appointment beforehand for the dating scan. The female is usually asked to carry out the scan with a full bladder.
  • The subsequent measurement is usually carried out if the parents agree to it. Feel free to ask as many questions as you may have and the importance of the scan.
  • Do not forget the date of the future scan and be present at the hospital before the given time.
  • If you find any abnormality, seek medical advice for further management of the condition, and do not be ignorant of it.
  • Asking to determine the baby’s sex is illegal and a criminal offense and one can be punished for that.

Also, read Celebrities with Turner Syndrome.

7. Frequently Asked Questions 

7.1. Is the ultrasound scary?

At first, a newly pregnant woman might feel overwhelmed with the process and time. However, the process is completely safe and helpful for the mother and the child.

7.2. What questions should I ask at my 12-week scan?

You can ask about the procedure of the ultrasound and get counseling for the same before starting. Also, you can ask questions about the baby’s development, age, and delivery date and other questions can be what clothes to wear for the ultrasound and other related questions.

7.3. Is the first trimester over at 12 or 14 weeks?

The first-trimester duration starts from the 1st week till the end of the 12th week. The second trimester will start from week 13.

7.4. Are 13 weeks safe to announce pregnancy?

The person can announce their pregnancy whenever they feel like it. However, people prefer to announce it after the first trimester as the risk of miscarriage is much lower after the first trimester

  1. Richter, Joel D., and Xinyu Zhao. “The molecular biology of FMRP: new insights into fragile X syndrome.” Nature Reviews Neuroscience 22.4 (2021): 209-222. ↩︎
  2. Furman, Benjamin LS, et al. “Sex chromosome evolution: so many exceptions to the rules.” Genome biology and evolution 12.6 (2020): 750-763. ↩︎
  3. Al-Dhabyani, Walid, et al. “Dataset of breast ultrasound images.” Data in brief 28 (2020): 104863. ↩︎
  4. Saravanan, Ponnusamy, et al. “Gestational diabetes: opportunities for improving maternal and child health.” The Lancet Diabetes & Endocrinology 8.9 (2020): 793-800. ↩︎

Last Updated on by Suchi


Diksha Jagwani

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