Contents:
Medical Video: Contraction stress test
Definition
What is a contraction stress test?
Contraction stress tests function to check whether the condition of the baby (fetus) remains healthy during oxygen reduction which usually occurs when contractions occur when you are working. This test monitors the fetal heart rate. This test is done when the gestational age is at 34 weeks or more.
During uterine contractions, blood supply and oxygen are given to your baby in a short time. This is not a problem for most babies. However, the heart rate in some babies may decrease. This change in heart rate can be seen on an external fetal monitoring device.
During a contraction stress test, the hormone oxytocin is injected into you through a vein (intravenously, or IV) to trigger labor contractions. You may also be asked to massage your nipple area to remove oxytocin. If your baby's heart rate decelerates in a certain pattern rather than accelerating after a contraction, maybe your baby has a problem with normal labor.
Contraction stress tests are usually performed if you undergo an abnormal nonstress test or biophysical profile. A biophysical profile uses ultrasound when a nonstress test is performed to determine the characteristics of your baby. There may be more than one contraction when the test is done.
When should I undergo a contraction stress test?
A contraction stress test is performed to check:
- does your baby stay healthy during the reduction of oxygen that appears when you are working
- Is the placenta healthy and has a good effect on your baby
A contraction stress test may also be performed if the results of a nonstress test or biophysical profile are not normal.
Prevention & warning
What should I know before undergoing a contraction stress test?
Contraction stress tests may show a decrease when your baby does not have a problem. This result is called false-positive result (false positive results). For some reason, contraction stress tests are rarely done now. In most cases, practitioners can review babies more quickly and safely by testing biophysical profiles during non-stress tests, or both. Some doctors may do biophysical profiles or dopple ultrasound tests rather than contraction stress tests.
Process
What should I do before undergoing a contraction stress test?
You may be asked not to eat or drink anything for 4 to 8 hours before the test is done. Empty your bladder before the test. If you smoke, you must stop smoking 2 hours before the test is done, because smoking can cause activity and the baby's heart rate to decline. You are asked to sign a file stating that you understand the risks that can occur and agree with the conditions.
Talk to your doctor about all things related to the test, such as the risk, how the test is done, and the results of the test.
How is the contract stress test process?
You will be asked not to eat or drink anything 6 to 8 hours before the test, because sometimes this test can proceed to emergency caesarean section (you should empty your bladder and urinate before the test). When the test is done, you are asked to lie on your left side. A technician will wrap two devices in your stomach: one to monitor the baby's heart rate; and others to record contractions in the uterus. The machine records the baby's contractions and heart rate on two different graphs. The test is done until there are three contractions in 10 minutes, usually occurring for 40 to 60 seconds. This test can occur for 2 hours. You may not feel a contraction or may just feel cramps like during menstruation, will not induce labor.
If no contractions occur during the first 15 minutes, the practitioner might try to give synthetic oxytocin (pitocin) in small doses through IV to stimulate the nipple, removing natural oxytocin.
What should I do after undergoing a contraction stress test?
After the test, you will usually be monitored until no more contractions or contractions decrease as before before the test is done. This contraction stress test may occur for 2 hours.
Explanation of Test Results
What do the test results mean?
The test results explain the health condition of your baby for a week. This test may have to be done more than once during pregnancy.
| Contraction stress test | |
| Normal: | Normal test results are called negative Your baby's heart rate remains and gets weaker after contraction. Note: There is a possibility that your baby will experience deceleration (weakening heart rate), but this condition will not last long, so it is not a serious problem. If a 10-minute contraction of your nipple stimulation or an oxytocin and deceleration infusion does not occur late, the baby's heart rate is expected to be controlled. |
| Abnormal | Abnormal test results are called positive. Baby's heart rate weakens (decelerates) and remains weak after contraction. This occurs when mid contractions. Slow contractions may mean that there is a problem with your baby. |
What affects the test results?
Some reasons why you cannot do this test, or the test results may be inaccurate, including:
- problems in previous pregnancies, such as vertical incisions. This test should also not be done if you have twins or more, or if you are prescribed sulfate during pregnancy
- ever uterine surgery. Strong contractions can cause the uterus to tear
- if you smoke
- movement in the baby during the test because it is very difficult to record the heart rate and contraction of the baby
