Special Tests for Monitoring Foetal Health
Why are special tests recommended to monitor foetal health?
Special tests to monitor the health of the foetus are carried out when there is an increased risk of complications during pregnancy. This can be due to pre-existing health conditions in the mother such as diabetes or heart disease; problems that arise during pregnancy such as high blood pressure, Rh incompatibility and foetal growth problems; decreased movement of the foetus, a post term pregnancy or multiple pregnancy.
When are special tests carried out?
Your doctor usually recommends special testing after 32 weeks of pregnancy, but it may be performed earlier if needed. The tests may be repeated on a periodic basis.
What are the common special tests?
Common special tests include non-stress test, foetal movement counts, biophysical profile, Doppler ultrasound and contraction stress test.
What is the non-stress test?
The non-stress test measures foetal heart rate over a given period with no stress placed on the foetus. The test takes 20 minutes and may be performed while reclining or lying down. Foetal heart rate is measured by a belt with a sensor which is placed around your abdomen. The number of accelerations in heart rate over the 20-minute period helps your doctor determine your baby’s health.
What are foetal movement counts?
Foetal movement counts may be recommended if you feel your baby’s movements have decreased. This test is performed by counting the number of times your baby moves or kicks in the womb over a certain period. Your doctor can show you different ways to perform this test.
What is biophysical profile?
Biophysical profile (BPP) evaluates your baby’s health on 5 parameters: foetal heart rate, breathing movements, body movements, muscle tone and the quantity of amniotic fluid. BPP uses a scoring system that gives each parameter a score of 0 or 2 points with a maximum total score of 10. It is performed by combining a non-stress test with an ultrasound evaluation.
How is the ultrasound test performed?
To perform an ultrasound test, your doctor gently rolls a device called a transducer over a gelled area on your abdomen. The transducer sends and receives sound waves that pass through your body bouncing off the internal structures. This information is used to create images of your baby which are displayed on a screen.
What is the Doppler ultrasound?
A Doppler ultrasound is performed to evaluate blood flow through the vessels. Sound waves echo off the blood cells flowing through the vessel to create images. A Doppler ultrasound can be used to study the umbilical artery which carries blood from the foetus to the placenta through the umbilical cord.
What is the contraction stress test?
The contraction stress test is performed to see how your baby responds to the stress of uterine contractions. Contractions are simulated by giving certain medicines or by other means. As with the non-stress test, foetal heart rate is monitored by a belt with a sensor worn on the abdomen.