Electronic Fetal Heart Monitoring
Internal monitoring can be
done only after your
cervix has dilated to at least 2 centimeters (cm) and
amniotic sac has ruptured. Once started, internal
monitoring is done continuously.
For internal monitoring, a sensor
is attached to your thigh with a strap. A thin wire (electrode) from the sensor
is inserted through your vagina and cervix into your uterus. The electrode is
then attached to your baby's scalp. Your baby's heartbeat may be heard as a
beeping sound or printed out on a chart. Internal monitoring does not use
reflected sound waves (ultrasound) for monitoring.
A small tube
that measures uterine contractions may be placed in your uterus next to your
baby. The strength and timing of your uterine contractions is usually printed
out on a chart.
Internal monitoring is more accurate than external
monitoring for keeping track of your baby's heart rate and your
Why It Is Done
External fetal heart monitoring
External fetal heart monitoring is done to:
- Keep track of your baby's heart
- Measure how often you have a contraction and how long your
contractions last during labor and delivery.
- Find out whether you
- 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
- 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
high blood pressure (hypertension) or if you are over 41
Internal fetal heart monitoring
Internal fetal heart monitoring is
- Find out if the stress of labor is
threatening your baby's health.
- Measure the strength and duration
of your labor contractions.