What can I expect from non-stress test (NST)?

Paula Greer
Midwifery Nursing

Non-stress tests are performed in the third trimester and are done to monitor your baby's heart rate and to look for accelerations in your baby’s baseline heart rhythm.

They will place you on the fetal heart rate monitor and establish your baby’s baseline heart rhythm. You will need to have at least a 20-minute strip for the test and they will be looking for at least 2 accelerations of your baby’s heart rate of at least 15 beats per minute for at least 15 seconds to call your strip reactive.

It helps to eat prior to having your test, as your baby will be less likely to be asleep after you have eaten. If your baby is asleep the test will be longer and you ay need to drink something to help wake him/her up. Take a good book with you and use this time to catch up on your reading, as the test may be 20-40 minutes.

During a non-stress test (NST) the woman will be comfortably positioned in a semi reclining or lateral Sims position. An external fetal monitor is placed on the maternal abdomen to detect and record fetal cardiac activity. Fetal movement is documented with an event button, pushed by the woman when fetal movement is felt. The test will last a minimum of 20 minutes but may be extended to 40-45 minutes to allow for fetal sleep-wake cycles. At the completion of the test, the fetal monitor will be removed and the abdomen cleaned. The test will be interpreted and the results and plan for continued care will be share with the woman.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.