Why It Is Done
External fetal heart monitoring is done to:
Keep track of your baby's heart rate.
Measure how often you have a contraction and how long your contractions last during labor and delivery.
Find out whether you are having preterm labor.
Check on your baby's health if problems are suspected. External fetal heart monitoring will be done during a nonstress test to check your baby's heart rate while at rest and while moving. If your baby does not move during this test, more testing will be needed.
Check on your placenta to make sure that it is giving your baby enough oxygen. A contraction stress test that shows that your baby is not getting enough oxygen helps your doctor make decisions about the safest delivery method. If the test shows that your baby may be in danger, your doctor may recommend starting (inducing) labor early or may talk to you about doing a cesarean section (C-section).
Check your baby's health if your baby has not been growing normally (delayed fetal growth) or if you have diabetes, high blood pressure (hypertension), or are over 41 weeks pregnant.
Internal fetal heart monitoring is done to:
Find out whether the stress of labor is threatening your baby's health.
Measure the strength and duration of your labor contractions.
How To Prepare
You may be asked to eat a meal shortly before having a nonstress test, because digesting food often increases the movement of your baby.
If you are having a contraction stress test, you may be asked to not eat or drink for 4 to 8 hours before the test.
If you smoke, you will be asked to stop smoking for two hours before the external monitoring test because smoking decreases your baby's activity.