Ultrasounds
How are ultrasounds made?
An ultrasound is a commonly used and safe examination during pregnancy. Using sound waves, we can create images of the uterus and your baby. This allows us to monitor your baby’s growth and development and detect possible abnormalities early on. But how exactly does an ultrasound work, and what can you expect?
How does an ultrasound work?
An ultrasound uses a transducer — a small device that emits high-frequency sound waves. These sound waves bounce off organs, bones, and tissues, creating an image on the screen.
- Bones appear white on the image.
- Soft tissues and organs appear in shades of gray.
- Amniotic fluid appears black, as it lets sound waves pass through instead of reflecting them.
To improve image quality, a special gel is applied to your skin or to the transducer. This eliminates air bubbles that could interfere with the sound waves. An ultrasound is completely safe for you and your baby. It doesn’t use harmful radiation like X-rays. The sound waves are inaudible and have no negative effects on your baby.
Most ultrasounds are not painful, though you might feel some pressure when the transducer is pressed against your belly. For a transvaginal scan, the transducer is inserted into the vagina. This might feel a little uncomfortable, but it shouldn’t be painful.
What are the advantages and disadvantages of an ultrasound?
✅ Advantages of an ultrasound
- We can determine the gestational age accurately.
- We can rule out an ectopic pregnancy.
- The baby’s physical development can be assessed.
- We can adjust your care plan if something unusual is detected.
- Sometimes an ultrasound can confirm whether a baby is smaller or larger than expected.
❌ Disadvantages of an ultrasound
- Sometimes we find things you might rather not have known — such as a cleft lip or a minor abnormality that may not affect your baby’s health.
- Incidental findings can cause unnecessary worry. One example is a sonomarker* — a small irregularity that often has no significance but may still cause concern. Read more in our blog article.
- Unfortunately, the accuracy of ultrasound for estimating a baby’s growth is limited. Sometimes we may think a baby is too big or too small, which can lead to unnecessary medical interventions — and worry for parents.
Summary
- Ultrasounds use sound waves and are safe and painless.
- There are both abdominal and transvaginal scans, depending on how far along you are and what needs to be examined.
- Ultrasounds have many benefits, such as determining gestational age and ruling out certain conditions.
- Sometimes, however, an ultrasound can cause unnecessary concern by revealing harmless irregularities.
- If you have doubts or worries after a scan, talk to us — we’re here to help you understand everything clearly.