Skip to content
My WebMD Sign In, Sign Up

Health & Pregnancy

Font Size

Nonstress Test

A nonstress test is used in pregnant women to evaluate the heart rate of an developing baby (fetus). Normally, a developing baby's heart rate ranges from 100 to 160 beats per minute, and it usually speeds up after the baby moves. If the heart rate is faster or slower than this range or does not speed up after the baby moves, it may mean that the baby is not doing well.

During the test:

  • Elastic belts with two sensors are placed on the woman's belly. The sensors are connected to an electronic monitoring machine.
    • One sensor monitors the baby's heart rate.
    • The other sensor is a pressure gauge, which measures the strength and length of tightening (contractions) of the woman's uterus if they occur.
  • The woman pushes a button on the machine every time she feels the baby move.
  • The baby's heart rate is compared during movement and during contractions. Normally, the baby's heart rate increases when the baby moves. But the heart rate may not increase during the testing period.

A nonstress test usually takes about 30 minutes. It can be done in a hospital or the doctor's office.

ByHealthwise Staff
Primary Medical ReviewerSarah Marshall, MD - Family Medicine
Specialist Medical ReviewerAlan C. Dalkin, MD - Endocrinology
Last RevisedNovember 3, 2011

WebMD Medical Reference from Healthwise

Last Updated: November 03, 2011
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.

Pregnancy Week-By-Week Newsletter

Delivered right to your inbox, get pictures and facts on
what to expect each week of your pregnancy.

Today on WebMD

Woman smiling as she reads pregnancy test
Slideshow
pregnant woman with salad
Quiz
 
pregnancy am i pregnant
Article
calendar and baby buggy
Tool
 

slideshow fetal development
Slideshow
pregnancy first trimester warning signs
Article
 
What Causes Bipolar
Video
Woman trying on dress in store
Slideshow
 

pregnant woman
Article
Close up on eyes of baby breastfeeding
Video
 
healthtool pregnancy calendar
Tool
eddleman prepare your body pregnancy
Video