Non Stress Test – Everything You Need To Know

Non Stress Test

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Are you pregnant and have already begun your litany of tests? Does your doctor suggest list upon list of tests you are due? Has she spoken to you about the non-stress test? Do you wonder what the pregnancy non stress test is?

If your doctor schedules a non-stress test for you, and yet you have no idea what it entails, read our post and find out here.

What Is A Non-Stress Test?

A non-stress test or the fetal non-stress test or the fetal heart rate monitoring is a non-invasive test. Doctors usually perform it when you are more than 28 weeks pregnant. The test gets its name as it does not exert any pressure or stress on your unborn baby. It does not pose any form of physical risk to you or your baby. The non-stress test helps monitor your unborn baby’s heart rate and see how the heart rate responds to your baby’s movements.

[ Read: Essential Tests To Take During Pregnancy ]

When Is A Non-Stress Test Done?

If your doctor recommends a non-stress test, it does not mean you or your baby are at any risk. The test occurs so that your doctor gets crucial information about the oxygen supply that reaches your baby. The test helps provide information about whether or not your unborn baby is in need of any treatment or in case there is a need for immediate birthing.

Your unborn baby’s heart will start to beat rapidly later in your pregnancy whenever your baby is active. In case your unborn baby does not receive enough oxygen, it can cause disruption in the pathways to the heart and cause reduced activity.

There are various factors that your doctor will first check for before she decides whether or not you need to undergo a non-stress test. Some factors that she will consider; how healthy you are and how well your baby will survive if you face an early delivery. Here are a few conditions when your doctor may suggest you go for a non-stress test:

  • If you are pregnant with two or more babies and in case there are any complications for you or your babies.
  • In case you have any medical condition during your pregnancy or that can affect your baby. Some of the most common medical conditions that could warrant a non-stress test are thyroid disease, high blood pressure. Most blood disorders, lupus, type-1 diabetes, kidney disease or any form of heart disease also warrant the need for a non-stress test. (1)
  • When you are in the later stages of a post-term pregnancy, you are over two weeks from your due date but are yet to give birth.
  • If you have faced a pregnancy loss earlier
  • If your doctor feels that your unborn baby faces a decrease in the fetal movements or if there is any possible problem in your fetus’ growth.
  • In some cases, you may be experiencing a condition known as polyhydramnios, a condition in which your unborn baby has too much amniotic fluid around him (2). You could also be experiencing a condition known oligohydramnios, a condition in which your unborn baby has too little amniotic fluid around him (3). In case you have any of these conditions, your doctor will recommend a non-stress test.
  • Sometimes, a very dangerous condition known as Rh (rhesus) sensitization can occur during the second or a subsequent pregnancy (4). The condition occurs if your blood group is Rh negative while that of your baby is Rh positive.
  • In case your doctor is not happy with the results from other prenatal tests that have been done and requires further information.

Depending on your and your developing baby’s overall health, your doctor will suggest the frequency of the non-stress test. The test could be recommended for once or twice a week, and sometimes even as frequently as every day, depending on the need. If the doctor suspects that your baby is not getting enough oxygen, you will be placed on a non-stress test schedule on a daily basis. In case of any sudden negative health change in your unborn baby, your doctor may place you on a daily watch non-stress test as well. As these tests are non-invasive and cause no kind of distress to your unborn baby whatsoever, you do not have to worry about it.

[ Read: What Is The Rh Factor Test ]

Can A Non-Stress Test Cause Any Harm To You Or Your Unborn Baby?

A non-stress test does not necessarily cause any harm to either you or your unborn baby. However, there are certain factors that could potentially affect your health:

  • The test can cause you anxiety, which can lead to other health issues or cause distress to your unborn baby.
  • In some cases, the non-stress test may not be able to pick up on any existing health or medical issues that already exist.
  • Sometimes, the test can tell you about certain problems that don’t exist.

[ Read: Genetic Testing During Pregnancy ]

How Does The Non-Stress Test Work And How Is It Done?

The non-stress test helps record your baby’s heartbeat, movement, and even contractions. It notes any changes in the rhythm of your baby’s heart. Such changes occur at times when your baby might go from a resting to moving phase or when you experience contractions during labor. When your baby is active, the heartbeats will be more active than otherwise.

  • For the test to occur, you have to lie down on your back. Two belts will safely secure your belly.
  • Before the non-stress test begins, your doctor will conduct a blood pressure check. She might ask you to take another blood pressure check in the middle of the test.
  • One belt measures the heartbeat of your baby while the other will helps measure your uterine contractions.
  • Whenever you feel your baby move or kick you, you have to press a button attached to a cord and placed around your belly. Each time you press the button, it records the same on paper known as fetal heart record that is printed out at the end of the test with the results.
  • The graphs on the paper will help your doctor assess your baby’s heartbeats during any movements.
  • It takes only about 20 minutes to perform the non-stress test.
  • In case your baby is asleep at the time, the nurse or other medical staff may try to wake up the baby by gently tapping your belly or trying out other approved ways. Your doctor may ask you to drink a glass of juice and help wake your baby up. If your baby does not wake up still or there is hardly any noticeable movement, you might have to extend the test for another 20 minutes.(5)

[ Read: CBC Test During Pregnancy ]

Reading The Non-Stress Test Results:

Once the test finishes, your doctor will almost immediately discuss the results with you. Here are some key phrases that your doctor will most likely use to explain:

  • Reactive: 

If you have a reactive (normal) result before the 32nd week of your pregnancy, it indicates your baby’s heartbeat rises from a level to twice of it for at least 10 seconds within the first 20 minutes of testing. At your 32nd week of pregnancy, you will have a reactive (normal) result if your baby’s heartbeat goes from a certain level to twice of that for at least 15 seconds or more within the first 20 minutes of testing.

[ Read: Cardiotocography Test During Pregnancy ]

  • Non-Reactive: 

A non-reactive test result will mean that the result is not conclusive, and there is the need for further testing. The result is non-reactive when it does not match the criteria in the point above. While it can immediately start worrying you, a non-reactive result could also be because your baby was sleeping through the entire process.

In case you get a non-reactive non-stress test result, your doctor will refer some more prenatal tests, which will help assess your baby’s health. Some tests that you may be asked to go for are:

  • Biophysical Profile: 

It is a test in which a fetal non-stress test is combined with an ultrasound testing. The test helps check your baby’s movements, breathing, the level of amniotic fluid and muscle tone.

  • Contraction Stress Test: 

Doctors use the contraction stress test to check the way your baby’s heart rate reacts each time you experience a contraction in your uterus.

In some cases, your doctor may ask you to wait and take another non-stress test the same day or maybe the next day.

[ Read: Ultrasound During Pregnancy ]

In case of reading the tests, a reactive result is more accurate than a non-reactive one. In case you have had a non-reactive test result earlier and your second non-stress result is reactive, your doctor will go with the second test result.

Do not panic if your doctor refers you for a non-stress test. Make sure you speak to your doctor about the result and if any changes you need to make.

So, how was your experience with the non-stress test? Tell us your story here. Fellow moms would love to hear from you.

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Debolina Raja