How It Is Done
Most often, a biophysical profile (BPP) is performed by your
obstetrician. However, it may be done by an ultrasound
technologist or
radiologist. A BPP can be done in your doctor's
office, hospital, or clinic.
A
nonstress test with electronic fetal heart monitoring
and a fetal ultrasound may be done at the same time as a biophysical profile.
See an illustration of
fetal
ultrasound
and
external
monitoring
. A modified biophysical profile combines a nonstress test and
measurements of the amniotic fluid.
Nonstress test
External fetal heart monitoring records your baby's heart rate
while your baby is moving and not moving. It is usually done just before a
fetal ultrasound.
External monitoring is done using two flat devices (sensors) held
in place with elastic belts on your belly. One of these
uses reflected sound waves (ultrasound) to keep track of
your baby's heart rate; the other measures the duration of your contractions.
The sensors are connected to a machine that records the information. Your
baby's heartbeat may be heard as a beeping sound or printed out on a chart.
If your baby moves or you have a contraction, you will
be asked to push a button on the machine. Your baby's heart rate is
recorded and compared to the record of movement or your contractions. This test
usually lasts about 30 minutes.
Fetal ultrasound
Often you do not need to remove your clothes for the ultrasound
test; you can lift your shirt and push down the waistband of your skirt or
pants. If you are wearing a dress, you will be given a cloth or paper covering
to use during the test.
- You may need to have a full
bladder. You may be asked to drink 4 to 6 glasses of
liquid, usually juice or water, about an hour before the test. A full bladder
helps transmit sound waves and pushes the intestines out of the way of the
uterus. This makes the ultrasound picture clearer.
- You will not be able to urinate until the
test is over. However, tell the ultrasound technologist if your bladder is so
full that you are in pain.
- If you cannot drink enough liquid, your
bladder may be filled with sterile water through a thin flexible tube (urinary catheter) inserted through your
urethra.
- If an ultrasound is done during
the later part of pregnancy, a full bladder may not be needed. The growing
fetus will push the intestines out of the way.
- You will lie on your back on a padded
examination table. If you become short of breath or lightheaded while lying on
your back, your upper body may be raised or you may be turned on your side.
- A gel will be spread on your abdomen.
- A small,
handheld instrument called a transducer will be pressed against the gel on your
skin and moved across your abdomen several times. You may watch the monitor to
see the picture of the fetus during the test.
When the test is finished, the gel is cleaned off of your skin.
You can urinate as soon as the test is done. Transabdominal ultrasound takes
about 30 to 60 minutes.
Ultrasound technologists are trained to gather images of your
fetus but cannot tell you whether it looks normal or not. Your health
professional will share this information with you after the ultrasound images
have been reviewed by a
radiologist or
perinatologist.