What is ultrasound?
Ultrasound is like ordinary sound except it has a frequency (or pitch) higher than human beings can hear. When sent into the body from a transducer (scanner) resting on the patient's skin, the sound is reflected off internal structures. The returning echoes are received by the transducer and converted by an electronic instrument into an image of the internal structures on a viewing screen. Diagnostic ultrasound is commonly called sonography or ultrasonography.
Is ultrasound safe? There are no known harmful effects associated with the medical use of sonography. Studies in humans have revealed no direct link between the use of diagnostic ultrasound and any adverse outcome. Although the possibility exists that biological effects may be identified in the future, current information indicates that the benefits to patients far outweigh the risks, if any.
Why should I have an ultrasound exam?
The most common reason for having an ultrasound examination is to help your doctor determine when your baby is due, or to make sure your baby is growing as it should. Your doctor may also want an ultrasound examination to determine the baby's position, or to see if you are carrying twins or triplets. With ultrasound, the amount of fluid around your baby can be seen.
Is there any special preparation for the exam?
You will be asked to drink some water an hour before the examination. The reason for this is that it is easier to see the pregnancy by looking through a full bladder.
Who will perform the exam?
In most cases, you will be examined by a sonographer. The pictures will then be reviewed and read by a doctor. In some cases, you may also be examined by the radiologist.
Will it hurt?
There is no pain involved in an ultrasound examination. If you have been asked to fill your bladder, this may cause some discomfort. In early pregnancy it may be necessary to put a special transducer (scanner) in your vagina, so the very small baby can be seen. You will be able to empty your bladder before this type of exam is done. It will not hurt, but you may feel some pressure. It does not hurt the baby. For scanning, a gel like material is put on your abdomen and the transducer is placed on your skin. The gel makes it possible for the scanner to se through your skin into your body.
Can I see my baby move?
The baby's heartbeat and movement of its body, arms, and legs can be seen by ultrasound, depending on the age of the baby. The baby can be seen moving during an ultrasound examination many weeks before the mother can feel movement.
Does an ultrasound exam guarantee a normal baby?
No. The ability to detect abnormalities depends on many things. For instance, the size and position of your baby may not allow certain abnormalities to be seen. Some types of abnormalities cannot be seen because they are too small or not visible by ultrasound.
Will I need more than one ultrasound exam?
In many cases you may have only one exam, but for a variety of reasons, the physician may order additional scans during your pregnancy.