Why should I take the test?💡

The contraction test is also called a stress test or an oxytocin challenge test. It checks for any signs of stress during uterine contractions. When a decision to deliver has to be made but your healthcare practitioner is not sure whether the baby is healthy enough, external stimulus that makes your uterus contract is given to stimulate contractions that are similar to labor contractions but typically don’t start labor. 

You only need a contraction test if you have abnormal results after a nonstress test or biophysical profile. During a contraction, the blood flow to the placenta is slowed down, hence, the placenta’s extra storage of blood can provide the baby with the oxygen he needs if it is healthy. Signs of an unhealthy placenta can be detected if the baby’s heart beats more slowly due to lack of oxygen. 

How is the test done?💉

The contraction test is often performed when you are 34 or more weeks pregnant. Usually, you stop eating and drinking for four to eight hours before the test. 

If you smoke, you have to stop at least two hours before the test because smoking can decrease your baby’s heart rate and interfere with the test’s results. Then, after lying on your left side, the doctor will strap two devices to your belly. One monitors your baby’s heartbeat while the other records uterus contractions.

You will be given a small dose of oxytocin in an IV to stimulate contractions. The test can take up to two hours until you have had three contractions in a ten-minute window, each lasting 40 to 60 seconds. When the test is over, you will continue lying down to wait for your contractions to stop or go back to their pretest level.

TMI from Baby Billy👩‍⚕️:

Results of the test

Negative result:  A normal or negative result indicates that the baby’s heartbeat does not slow down in response to your contractions. The baby is probably doing fine in your tummy.

Positive result: If your baby’s heart beats more slowly after more than half of your contractions, the result signals that your baby may be under stress or incapable of tolerating labor contractions. In this case, the doctor may decide to do a cesarean section right away or continue observations. 

Equivocal results: Your baby’s heart reacts more with long-lasting contractions, or sometimes it slows down intermittently. 

Risks of the procedure

Your uterus will be hyperstimulated, causing contractions so strong and frequent that they halt blood flow to the baby. The test can also stimulate premature labor if you get too much oxytocin too quickly. Because the test carries these risks and is not fully reliable in most situations, the contraction test is not often conducted unless it is truly necessary.