Contraction Stress Test
How It Is Done continued...
The hormone oxytocin is given in a low dose and
increased until you have three contractions within 10 minutes, each one lasting
longer than 45 seconds. Or you may be asked to massage one of your nipples by
hand to start contractions. If you don't have a second contraction within 2
minutes of the first, you will massage your nipple again. If contractions do
not occur within 15 minutes, you will stimulate both nipples.
After the test, you will be watched until your contractions go away or
slow down to what they were before the test. A contraction stress test may take
How It Feels
You may need to lie on your left side for
the test. This position may be uncomfortable or painful when you are having
labor contractions. The belts holding the sensors may be uncomfortable. Most
women say this test is uncomfortable but not painful.
Fetal heart monitoring may indicate that your baby is having problems when your baby is actually healthy. Fetal heart
monitoring can't detect every type of problem, such as a birth defect.
The risks from having oxytocin include:
- Causing labor to start earlier than your
expected delivery date.
- Causing prolonged contractions that may
cause problems with your baby. The contractions usually stop when the oxytocin
is stopped. You may be given a medicine to stop the contractions. If in the
very rare case that your contractions do not stop, your doctor may recommend
A contraction stress test checks to see
if your unborn baby (fetus) will
stay healthy during the reduced oxygen levels that normally occur during
contractions when you are in labor.
Results of the test tell your
baby's health for 1 week. The test may need to be done more than once during
Contraction stress test
Normal test results are called negative.
baby's heart rate does not get slower (decelerate) and stay slow after the
contraction (late decelerations). Note: There may be a
few times during the test when your baby's heart rate decelerates, but it
doesn't stay slow so it is not a problem.
If three contractions
occur during a 10-minute period of nipple stimulation or oxytocin infusion and
there are no late decelerations in your baby's heart rate, your baby is
expected to be able to handle the stress of labor.
Abnormal test results are called positive.
baby's heart rate gets slower (decelerates) and stays slow after the
contraction (late decelerations). This happens on more than half of the contractions.
Late decelerations may
mean that your baby will have problems during normal labor.
What Affects the Test
Reasons you may not be able to
have the test or why the results may not be helpful include:
- Past pregnancy problems, such as a
cesarean section with a midline (vertical) incision,
placenta previa, or
placenta abruptio. The test also is not recommended if
you are pregnant with more than one baby, are likely to have premature
rupture of the
membranes (PROM), have an
incompetent cervix, or have been given magnesium
sulfate during your pregnancy.
- A uterine surgery in the past. Strong
contractions may cause the uterus to rupture.
- If you smoke or use
- Movements of your baby during the test. It may be hard for
the sensors to record your baby's heart rate or contractions.
Being very overweight.