- What is ultrasound? Ultrasound is like ordinary
sound except it has a frequency (or pitch) higher than people can
hear. Ultrasound is sent into the body from a scanning instrument
(transducer) placed on your skin. The sound is reflected off
structures inside your body and is analyzed by a computer to make
an image of these structures on a monitor, which is similar to a
television screen. The moving pictures can be recorded on film.
Diagnostic ultrasound is commonly called sonography or
- Why do patients have a targeted obstetric ultrasound examination?
The most common reason for having a targeted ultrasound
examination is to help your doctor determine when your baby is
due, to make sure your baby is growing appropriately, and to look
for structural abnormalities. Your doctor may also want an
ultrasound examination to determine the baby's position or to see
if you are carrying more than one baby. With an ultrasound
examination, the amount of fluid around your baby can also be seen.
- Are there any special preparations needed for the ultrasound examination?
In most cases, no special preparation is needed for the
examination. In some cases, your doctor may recommend an
endovaginal ultrasound study, which involves the use of a special
transducer in your vagina, to improve visualization of your baby
or your cervix.
- Who will perform the examination? One of our
Registered Diagnostic Medical Sonographers will perform your
ultrasound. The images captured during the procedure will be
reviewed and read by the doctor immediately following your
- Will the ultrasound hurt? There is no pain from an
ultrasound examination. Patients may feel some pressure from an
endovaginal ultrasound examination in which a probe is inserted
into the patient's vagina; the probe is the size of a tampon and
is smaller than a speculum. The ultrasound examination does not
affect your pregnancy.
During the scanning procedure, a gel-like material is put on the
patient's abdomen and a transducer is placed on the skin. The gel
makes it possible for the ultrasound system to see through your
skin into your body. The gel wipes off easily and does not usually
stain clothing, but it is a good idea to wear clothes that are
- Can I see my baby move? Your baby's heartbeat and
movement of his or her body, arms and legs can be seen using
ultrasound, depending on the age of the baby. Your baby can be
seen moving during an ultrasound examination many weeks before you
can feel movement.
- Will I learn the sex of my baby? Sometimes it is
possible to see the sex of the baby and sometimes it is not.
If your baby is lying in an inconvenient position the baby's sex
may not be determined.
- Does an ultrasound examination guarantee a normal baby?
No, an ultrasound examination does not guarantee a normal baby.
The ability to detect fetal 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
- What is Doppler ultrasound? Doppler ultrasound is a
special form of ultrasound. This type of ultrasound is useful in
evaluating blood flow to the pelvic organs and fetal vessels.
The doctor or sonographer performing the scan can display this
information in several ways. An audible sound may be used, or the
blood flow may be shown as a graphic or color display. It is not
painful. The decision to use Doppler ultrasound is often not
made by the doctor until the time of the exam; for example, for
further evaluation of the heart of the fetus. It is not
considered harmful to the fetus.
- Is ultrasound safe? The AIUM has a Bioeffects
Committee that meets regularly to consider safety issues and
evaluate reports dealing with bioeffects and the safety of
ultrasound. The AIUM has adopted the following official
statement: "There are no known harmful effects associated with
the medical use of sonography. Widespread clinical use of
diagnostic ultrasound for many years has not revealed any harmful
effects. Studies in humans have revealed no direct link between
the use of diagnostic ultrasound and any adverse outcome.
Although the possiblity exists that biological effects may be identified
in the future, current information indicates that the benefits to
patients far outweigh the risks, if any.