How Do Ultrasounds Work?

An ultrasound (also called a sonogram) is a safe, painless imaging technique that uses sound waves to create pictures of your baby inside the womb. It helps doctors check on your baby’s growth and development and can offer reassurance that everything is going well.

Ultrasounds use high-frequency sound waves, which are too high to be heard by the human ear. Here’s a quick breakdown of how the process works:

• The Transducer: This is a small handheld device that sends out sound waves and picks them back up when they bounce off structures in the body.
• The Gel: A special gel is applied to your belly to help the sound waves travel smoothly from the transducer into your body.
• The Sound Waves: As the sound waves hit the baby (and everything else inside), they bounce back. The machine collects these echoes and turns them into an image on a screen.
• The Image: The result is a real-time black-and-white image that shows your baby’s position, heartbeat, and movement.

There are several kinds of ultrasounds you might experience during pregnancy:

• Transabdominal Ultrasound: The most common type—gel on the belly, transducer on top.
• Transvaginal Ultrasound: Often used in early pregnancy; the transducer is gently inserted into the vagina to get a closer look.
• 3D and 4D Ultrasounds: These offer more detailed images and even video. They’re often used to look more closely at facial features or detect certain conditions.
• Doppler Ultrasound: Used to measure blood flow and check the baby’s heart and placenta function.

Most women will have at least two standard ultrasounds during pregnancy:

• Dating Ultrasound (around 6–13 weeks): Confirms pregnancy, estimates due date, and checks for multiples.
• Anatomy Scan (around 18–22 weeks): A detailed look at baby’s organs, bones, and overall growth. This is when many parents find out the baby’s sex (if they want to!).

Additional ultrasounds may be recommended if there are specific concerns or complications.

Yes! Ultrasounds have been used safely in pregnancy for decades. They don’t use radiation like X-rays and are considered low risk for both mother and baby.

Early on, you might just see a tiny flickering heartbeat. Later in pregnancy, ultrasounds can show your baby sucking their thumb, moving around, or even yawning! It’s one of the most exciting moments for many parents-to-be.