A prenatal ultrasound test uses high-frequency sound waves to produce images of your baby and the placenta. As well as being used to establish your baby’s due date an ultrasound is also used to:
- detect a multiple pregnancy
- determine the position of your baby
- check the amniotic fluid around the baby
- check the baby’s heart beat
- determine the position of placenta
- check for some major abnormalities
An ultrasound is completely harmless and depending on your hospital is usually performed at 18-22 weeks of pregnancy.
You will have at least one ultrasound during your pregnancy however, your doctor may want to do more ultrasounds to check on your baby’s growth or condition.