What are the Implications of Non Stress Test for Your Baby?

One of the most common prenatal tests is NST (Non-Stress Test) and which is done to check the health of your baby. As the name suggests, nothing will be done during the test so that the baby stresses out. It is just done to monitor your baby’s heart rate. Without troubling your baby, it’s a delightful sight to observe your baby’s natural activities. Your baby’s heart rate is measured when the baby is sleeping in the womb. The doctor will measure the heart rate of the baby with the activity level of your baby and both of them should equally match up to give good results. The positive results will assure you that the baby is receiving a sufficient amount of oxygen and nutrients for survival. The doctor will suggest you undergo the NST only if he/she is suspicious of fetal mortality. The test is done only after the 26th or 28th week of your pregnancy and is completely non-invasive.

When is the NST (Non-Stress Test) Done?

Your doctor will recommend this test in the following situations:

• Twin or multiple pregnancies with certain complications.

• If you are a patient with gestational diabetes, heart diabetes, hypertension, or if you have high blood pressure levels

• Delayed or halted development of the baby in the womb

• A decrease in the baby’s activity or movement in the womb

• Oligohydramnios- Less amniotic fluid

• Post-term pregnancy (You’ve crossed your due date)

• Decreased fetal movements

• History of complications in previous pregnancy like miscarriage, stillborn child, premature baby or loss of the baby

• Rhesus sensitization (Rh)

• Birth defect or abnormality suspected in the baby

What happens in the Non-Stress Test?

You don’t need to do any special kind of preparation for this test. You have to stay calm because the doctor has put you under this test because there is a high risk of pregnancy loss. The test is usually done by a trained healthcare provider and your blood pressure levels are monitored before starting the process. During the process, you’ll be made to lie on a reclining chair and the technician will tie two-strap devices to your abdomen. One will monitor the baby’s heartbeat and the other one will record the contractions in your uterus. The technician will carefully listen to the heartbeats of your baby and the contractions will be recorded on a piece of paper. The technician can easily watch the heart rate and body movements of the baby.

There is no need to panic if your baby is not moving, He/she might be sleeping. You might have to drink soda or water to wake your baby up or the technician will try to wake up the baby with the help of a buzzer. The duration of the test is approximately 20 to 60 minutes. The result of NST can be obtained immediately after it is performed.

What are the Results of the Non-Stress Test?

The result of the Non-Stress Test (NST) can be of two kinds:

1. Reactive

The results are considered normal if your baby’s heart rate is normal and the baby moves a lot. If your test happens before 32 weeks the heart rate of the baby must have gone above the baseline twice for at least 10 seconds within 20 minutes session. If your test happens after 32 weeks then the length increases up to 15.

2. Non-Reactive

It simply means your baby didn’t meet the above-mentioned criteria and non-reactive results occur simply because the baby is not active or sleeping during the test.

What Happens if the Result is Non-Reactive?

Even if the test results are non-reactive, sometimes doctors are also not sure whether it's due to a poor oxygen supply, any genetic defects, fetal sleep pattern, or maternal medication. To know the accurate reason your doctor may advise you to undergo some other tests if the results are non-reactive:

1. Contraction Stress Test

This test determines whether the pregnant lady will undergo stressful labor and preterm delivery or not. The doctor will ask you to take a medicine and will check the contractions.

2. Biophysical Profile

After this test, the doctor will tell you well in advance about your due date and if the fetal breathing rate, body structure, and the amniotic fluid in the uterus are appropriate or not. If not, then the chances of early delivery are quite possible and the doctor will advise you accordingly.

Conclusion

Like many other prenatal tests performed during pregnancy, Non-Stress Test (NST) is just another prenatal test, done to ensure the well-being of your baby. Reading about the NST before you undergo it can help to alleviate your stress and anxiety about it. We hope you liked the article!

References

1. Otto D. Umana. (2022). Prenatal Non-stress Test. statpearls.com

2. SINGH, Shreya; PREMI, H. K.; GUPTA, Ranjana. (2020). The role of non-stress test as a method to evaluate the outcome of high-risk pregnancy: a tertiary care center experience. International Surgery Journal