Ultrasound scans: an overview

ultrasound photo surrounded by string lights

Table of Contents

Ultrasounds are common nowadays and are vital tests to determine how your baby is developing. High frequency waves go through your skin and reflect when they reach the baby and the echo is transformed into an image. Bones are shown as white, soft tissues are grey and liquid appears black (doesn’t reflect the waves). A trained sonographer will be able to read these images and find out how your baby is developing.

For parents-to-be, it’s the first time to actually see the baby, and you probably receive a photo of your scan to keep as a memento. Although no side-effects are known, you don’t have to go for a scan if you prefer not to.

Why go for an ultrasound?

Ultrasounds can be done at any stage during pregnancy, and will not affect your baby in any way.

  • Check for a heartbeat
  • Check how many babies (single or twin pregnancy)
  • Diagnose an ectopic pregnancy, or check any form of bleeding
  • Date your pregnancy
  • Nuchal translucency scan to assess your baby’s chances of having Down’s syndrome
  • 20 weeks scan to see if all internal organs have developed normally
  • Check rate of growth
  • Diagnose abnormalities
  • Check the health of the placenta and amniotic fluid
  • Check position of the baby just before delivery (35-37 weeks)
  • Determine sex of the baby (not 100% accurate!). Note that not all hospitals are prepared to tell you this information.

When should I go for a scan?

  • First trimester: Your first will be to date your pregnancy, usually between weeks 10 and 14. This is important, not only to set your due date, but also for other tests that need to be done on certain dates, like the nuchal translucency scan.
  • Second trimester: Most commonly, this is the anomaly scan performed at 20 weeks. This checks that all your baby’s internal organs have developed normally.
  • Third trimester: Most hospitals send you for a scan at around 35-37 weeks to check the position of your baby. You may also be sent for a scan if your baby feels too small for his gestational age.

What happens if there’s a problem?

Although scan are ideal tools to see how you baby’s developing, in most cases, however, a definite diagnosis cannot be made and it’s just an indication that something is wrong with your baby. Based on these results, your doctor may send you to do an amniocentesis or other tests. In extreme cases, families may be faced with the decision as to continue or not with the pregnancy.

How is it done?

You’ll be asked to drink some water before your test, so that your baby is pushed up and a better image can be obtained. The sonographer will put some gel on your tummy, so that the transducer moves easily. In some cases you may need a vaginal scan. In this case, a long and thin vaginal transducer is placed inside your vagina to get a better picture of your baby.

Leave a Reply