A biophysical profile (BPP) test measures the health of your baby (fetus) during pregnancy. A BPP test includes a fetal ultrasound and usually includes a nonstress test. The BPP measures your baby's heart rate, muscle tone, movement, breathing, and the amount of amniotic fluid around your baby.
A BPP is commonly done in the last trimester of pregnancy. If there is a chance that your baby may have problems during your pregnancy (high-risk pregnancy), a BPP may be done by 32 to 34 weeks or earlier. For high-risk pregnancies, this test may be done every week or twice a week in the third trimester.
Why It Is Done
A BPP test is done to help check your baby's health during your pregnancy. It may be done if you have:
- Bleeding problems.
- Chronic kidney disease.
- Type 1 diabetes or gestational diabetes.
- High blood pressure (hypertension).
- A small amount of amniotic fluid (oligohydramnios) or too much amniotic fluid (polyhydramnios).
- A multiple pregnancy (such as twins or triplets).
- A pregnancy that has gone past your due date, between 40 and 42 weeks.
- Abnormal results on a nonstress test.
How To Prepare
- If you smoke, you will be asked to stop smoking for 2 hours before testing. This is because smoking affects the baby's heart rate and movements.
- You may be asked to drink water or other liquids just before testing. You will be able to empty your bladder after the test.
How It Is Done
The BPP includes a fetal ultrasound and usually includes a nonstress test. For the tests, you will lie back on a padded exam table. If you become short of breath or lightheaded while lying on your back, say so. The technician can help you change your position.
- Two elastic belts with sensors are placed across your belly. One sensor tracks your baby's heart rate with reflected sound waves (Doppler ultrasound). The other sensor measures how long your contractions are, if you are having any.
- You may hear your baby's heartbeat as a beeping sound. You may see it printed out on a chart.
- You may be asked to push a button on the machine when your baby moves or you have a contraction. This helps your doctor look at how your baby's heart reacts to movement and contractions.
- If there isn't much movement, it may be because the baby is asleep. If this happens during your test, the technician may try to wake the baby with a loud noise or by having you eat or drink something.
- A gel will be spread on your belly. This helps the passage of sound waves.
- A small, handheld sensor will be pressed against the gel on your skin and moved across your belly a few times.
- You may be able to watch the screen to see the picture of your baby during the test.
How long the test takes
- The nonstress test will take about 20 to 40 minutes.
- The fetal ultrasound will take about 30 to 60 minutes.
How It Feels
Lying on your back (or side) during the test may be uncomfortable. During a fetal ultrasound, the gel may feel cool when it is first applied to your stomach. You will feel a light pressure from the transducer as it passes over your abdomen.
There is very little chance of either you or the baby having a problem from a BPP. But you may feel anxious if the ultrasound reveals a problem with your pregnancy or baby. A nonstress test may falsely show distress in a baby that is actually healthy.
The results are scores on five measurements in a 30-minute observation period. Each measurement has a score of 2 points if normal and 0 points if not normal.
Some BPPs don't include all the measurements. When all five measurements are taken, a score of 8 or 10 points means that your baby is healthy. A score of 6 points means that you may need to be retested in 24 hours. A score of 4 or less may mean the baby is having problems. Depending on how far along you are in your pregnancy, your doctor may recommend delivery if you have a score of 6 points or less.