Ultrasound Scans during Pregnancy – Types, How to Prepare & more

Pregnancy ultrasound scan

An ultrasound scan sends high-frequency sound waves to the uterus during pregnancy to capture the image of the foetus. Images in ultrasound scans reveal the developmental phases of the body, often revealing bones and tissues through shades of white and grey.

What is An Ultrasound Scan?

An ultrasound scan is used to get a sneak peek at your baby and analyse how the foetus is faring inside the womb. It’s primarily used to detect signs of abnormalities and monitor the growth of the foetus. However, the gender of the baby is not revealed through these since that is considered illegal in India. Nowadays, 4D and 3D colour scans are popular ultrasound choices during pregnancy for revealing high-quality images of babies.

Are There Any Risks or Side-Effects of Ultrasounds During Pregnancy?

For over 40 years, ultrasound scans have been used during pregnancies with no known side-effects caused during the process related to –

  • Vision
  • Birth Weight
  • Causing Cancers
  • Hearing
  • Dyslexia
  • Birth Defects

When and Why You Need Sonography in Pregnancy?

You need sonography (ultrasound scan) during pregnancy to confirm if the fertilized egg has implanted in the placenta. Here are a few reasons why you need it-

  • To prevent ectopic pregnancies
  • To prevent pregnancy complications like molar pregnancies and miscarriage
  • To check whether or not you’re pregnant
  • To assess the growth and development of the foetus
  • To scan for birth defects and genetic abnormalities
  • As part of other prenatal tests such as Chorionic Villus Sampling


During First Trimester

During the first trimester of your pregnancy, you will-

  • Go through a viability scan and a dating scan during the first 6 weeks to 9 weeks, which will be followed up by an NT scan between 9 and 11 weeks.
  • Discover your due date through an ultrasound scan.
  • Listen to your baby’s heartbeat for the first time in around 6 weeks.
  • Check how many babies are in your womb and confirm if they are in the right position in the uterus.
  • Check for signs of spotting or excessive bleeding through images produced from the above scans.

During Second Trimester

During the second trimester, you will-

  • Know the baby’s gender (not applicable to India).
  • Assess the foetus’ growth and position inside the womb.
  • Scan for congenital abnormalities and birth defects.
  • Learn whether your baby has Down Syndrome.

During Third Trimester

During the third trimester, you will-

  • Go through a transabdominal ultrasound scan and a transvaginal ultrasound scan.
  • Review any anomalies or changes in the anatomy of the baby.
  • Review the position of the baby.
  • Check whether the baby is growing well according to medical diagnostic reports.

How to Prepare for UltraSound Scan in Pregnancy?

Before you prepare for an ultrasound scan for pregnancy, your bladder will need to be full in order to clearly scan for a high-quality image of the foetus. Make sure you drink two to three-ounce glasses of water one hour before your scheduled ultrasound scan comes up. Remember to have a full bladder during your appointment and do not urinate before the scan.

How is UltraSound Done During Pregnancy?

The ultrasound scan is a very simple procedure for first-timers. You basically lie down on the examination table and let the technician apply a special gel on your abdomen and pelvic area. This gel improves contact between the womb and the transducer so that waves travel properly through your belly. The transducer which looks like a small wand is finally placed on your belly, and as it moves, black and white images are captured on screen. You may be asked to move or hold your breath during this process.

Pregnant lady's ultrasound scan

Once the scan is satisfactory, and images are captured well, the gel is removed from your abdomen, and you will then be allowed to urinate or empty your bladder.

Will Sonography Hurt?

Under normal circumstances, sonography doesn’t hurt; however, in the event, you have pelvic injuries or existing abdominal pain, the pressure exerted by the transducer during the ultrasound might hurt or be a bit painful.

Different Types of UltraSounds Offered in Pregnancy

There are different types of ultrasounds offered during pregnancy. They are-

  1. Transvaginal Ultrasound – A probe is inserted into your vagina and is used for capturing clear images. This is used during the early stages of pregnancy.
  2. 3-D Ultrasound – A more detailed ultrasound scan that displays the width, height, and depth of the fetus and its organs in images. A special probe and software are used, and it is only available in certain hospitals.
  3. 4-D Ultrasound – Also known as a ‘Dynamic 3-D Ultrasound,’ this scan creates an animated video of the fetus. This motion video captures multiple images of the baby’s facial expressions, movements and even shows the highlights and shadows. However, it requires special equipment.
  4. Fetal Echocardiography– This is used for diagnosing heart problems in the foetus and takes a longer amount of time to complete. It’s similar to a traditional pregnancy ultrasound.
  5. Transabdominal Ultrasound – Sends waves through your lower abdomen using a transducer and a special gel. Images are captured in shades of black and white to depict foetal growth and abnormalities.
  6. Doppler Ultrasound – A type of ultrasound that’s used to assess your baby’s blood flow to the heart. A thin transducer is used to listen to your baby’s heartbeat in this procedure.
  7. Dating and Viability Scan – Used to confirm pregnancy status in women during the first 6 to 9 weeks.


Here are a few of the most commonly asked questions with regards to an ultrasound scan during pregnancy.

1. Is There Any Problem If the UltraSound is Performed At 6 to 7 Weeks and a Heartbeat is Not Detected?

No. Hearing no heartbeat is normal during the early stages of pregnancy as long as the foetus is shown to be developing.

2. Are Ultrasound Scans Accurate in Calculating Gestational Age?

An ultrasound scan is accurate in calculating the gestational age of the baby only during the early weeks of pregnancy and not later on.

3. Why Do Some Gynaecologists Schedule Ultrasound Scans Differently?

Some gynaecologists schedule ultrasound scans differently based on the foetus’ growth and condition during pregnancy. Routine ultrasound scans are done as part of the prenatal testing procedure.

Pregnancy ultrasound scan

4. Are UltraSound Scans Accurate in Determining the Conception Date?

Any calculations that are done for determining the conception date after an ultrasound are only estimates and not truly accurate. The due date depends on the average length and regularity of a woman’s menstrual cycle.

5. Are UltraSounds a Significant Part of Prenatal Care?

Yes. Ultrasound scans are used at different stages of prenatal care.

Getting a sonogram in pregnancy is not only sound but effective too. Ultrasound scans are a necessity for finding out whether or not you’re pregnant and if you are, they are used for tracking changes and growth in the fetus. Consult your doctor regarding which type to go for during pregnancy based on your medical condition and comfort levels.

Also Read: Doppler Scan in Pregnancy