Contraction Stress Test
How It Is Done
A contraction stress test may be done in your doctor's office or hospital by a family medicine doctor or an obstetrician and a trained laboratory technician or nurse. You usually do not need to stay overnight.
During the test, you will lie on a bed with your back raised. You will be tilted a little to your left side so you will not have pressure on the blood vessels in your belly. Two belts with sensors will be placed around your belly. One belt holds the sensor that records your baby's heart rate; the other sensor measures your uterine contractions. Gel may be used on your skin with the heart rate sensors. The sensors are hooked to a recording unit. The heart rate monitor may be moved if your baby changes position. Your baby's heart rate and your contractions are recorded for 10 minutes. Your blood pressure and other vital signs are also recorded.
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 2 hours.
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 delivery.