Contraction Stress Test
A contraction stress test checks to see if your unborn baby (Reference fetus Opens New Window) will stay healthy during the reduced oxygen levels that normally occur during contractions when you are in labor. This test includes Reference external fetal heart monitoring Opens New Window Reference Opens New Window. The test is done when you are 34 or more weeks pregnant.
During a uterine contraction, the blood and oxygen supply to your baby drops for a short time. This is not a problem for most babies. But the heart rate of some babies gets slower. This change in heart rate can be seen on the external fetal monitoring device.
For a contraction stress test, the hormone oxytocin is given to you in a vein (Reference intravenously, or IV Opens New Window) to cause labor contractions. You may also massage your nipples. This tells your body to release oxytocin. If your baby's heart rate slows down (decelerates) in a certain pattern after a contraction instead of speeding up (accelerating), your baby may have problems with the stress of normal labor.
A contraction stress test is usually done if you have an abnormal nonstress test or Reference biophysical profile Opens New Window. A biophysical profile uses Reference ultrasound Opens New Window during a nonstress test to measure a series of physical characteristics of your baby. You may have more than one contraction stress test during your pregnancy.
Some doctors may do a biophysical profile or a Reference Doppler ultrasound Opens New Window test instead of a contraction stress test.
|By:||Reference Healthwise Staff||Last Revised: Reference June 18, 2012|
|Medical Review:||Reference Sarah Marshall, MD - Family Medicine
Reference William Gilbert, MD - Maternal and Fetal Medicine