And can it be dangerous to you and
your baby?
Just as your heartbeat changes from time to
time, it’s normal for your baby’s heart rate to also fluctuate. A baby’s heart
beats much faster than an adult’s – on average between 120 and 160 beats per
minute (healthy men have a pulse of about 60, for women it’s 80). Smoking,
alcohol and recreational drugs during pregnancy decrease the oxygen supply to
the baby and this quickens the baby’s heartbeat. Taking an extra-hot shower can
have the same effect. Lying on your back for too long in the bath can also
interfere with blood circulating to the placenta and may slow your baby’s
heart. These last two examples are short-lived and not dangerous for your baby
– but they should be avoided because they could stress your baby.
If you’re worried about your baby’s
movements in the second half of your pregnancy, and if there are signs of
problems such as high blood pressure, diabetes, the amount of amniotic fluid
(too much or too little) or if you lost a previous pregnancy, your
doctor/midwife may take the precaution of sending you for a non-stress test.
Taking
an extra-hot shower can have the same effect
This is a painless, non-invasive test to
check your baby’s heartbeat in relation to his movements. It may be done in the
consulting room or at the hospital. If the baby’s heartbeat stays within the
safety perimeters, no further tests will be needed. But if the baby’s heartbeat
does not score well, more tests will be done. If the condition is
life-threatening for the baby, it may be necessary to deliver the baby
prematurely. Fortunately this is very rare.
A non-stress test means that the baby’s
heartbeat is monitored according to his movements in the absence of
contractions. This test may take from 20 to 60 minutes depending on whether the
baby is awake or not. You should lie on your side and you will be given a
button to push every time your baby moves to record these movements on the
graph.
A
non-stress test means that the baby’s heartbeat is monitored according to his
movements in the absence of contractions.
An electronic fetal monitor is strapped
over your tummy at the point where the baby’s heartbeat is strongest. This unit
produces high-frequency sound waves that bounce off the baby’s heart, producing
echoes. These echoes are recorded onto graph paper. They’re also digitally
displayed and the sound of the baby’s heartbeat is amplified.
What your baby will be expected to do
ü
Your baby will have one or more “breathing” movement
of the lungs, each lasting 30 seconds.
ü
Your baby will move his body, arms and legs at
least three times in 30 minutes.
ü
Your baby will stretch and open and close his
hands at least once during the non-stress test.
ü
Your baby’s heartbeat will quicken with
movement, increasing the rate by 15 beats per minute for about 15 seconds at
least every 20 minutes during the test.
If your baby is sleeping during the test,
you can try to wake him by having something to eat or drink or changing your
position.
If the doctor is not happy with the baby’s
score, particularly if there are other medical problems such as anemia in the
baby (this can be caused by the couple’s blood-group incompatibility). The
presence of an infection, if the baby is small for dates or there is a problem
with oxygen and nutrition supply to the placenta, a contraction stress-test
will be necessary or the doctor may order a biophysical profile or ultrasound.
This more advanced test, with the help of a scan, will monitor the baby’s
movements as well as muscle tone, breathing movements, the health of the
placenta and the amount of amniotic fluid.
If
your baby is sleeping during the test, you can try to wake him by having
something to eat or drink or changing your position.
Follow-up tests
If the tests are all normal and you and
baby are healthy, there is no need for further tests. If you have a medical
problem or there is concern that your baby is at risk, the non-stress test may
be repeated once a week or more often if you are a diabetic. In more severe
cases, you may be admitted to hospital and retested after 24 hours. If the
score has deteriorated during this time, your baby may need to be delivered
early. If the pregnancy is 36 weeks or more and the baby is in danger of not
getting enough oxygen and the cervix is soft, labor may be induced.
One of the challenges of modern living,
particularly for pregnant women, is stress. Stress increases and prolongs
adrenaline levels that can affect other systems of the body, namely nerves, the
heart, the endocrine system and immunity. Having to go for a non-stress test
can be stressful in itself. It can cause you and your partner to worry about
eventualities that may never happen.
If
the tests are all normal and you and baby are healthy, there is no need for
further tests
If you’re going to antenatal classes,
discuss your concerns with your midwife. It’s good to remember that while
modern tests help your doctor to take extra precautions, your baby also has
reliable back-up systems and mother nature has sustained the life of babies for
a eons!
