Amniocentesis examines your unborn baby's new life
long before its birth. The contents of amniotic fluid
include cells from the baby's skin and other organs
which can be used to diagnose the baby's condition
should the need arise. Amniocentesis or amnio as it
is popularly known is an invasive procedure and it
basically entails amniotic fluid to be withdrawn from
the uterus.
Why do you need an Amnio?
• If you are over 35, the risk of having a baby
with Down's syndrome increases
• If the father is over 50 this procedure may
be advised
• You have had a screen positive result from
an earlier antenatal test and want some definite results
• You had a previous baby with a genetic disorder
• You have a family history of Down's
The need for an amnio also arises if there
is an increased risk of:
• Rhesus factor problems
• Congenital absence of the brain (anencephaly)
• Respiratory distress syndrome
• Congenital defects in the spinal cord and
column (spina bifida)
• Cystic fibrosis
• Hemophilia
• Duchene's muscular dystrophy
• Thalassaemia
• Sickle-cell anemia
• Antitrypsin deficiency
• Phenylketonuria
The Risk factor
The main risk is miscarriage. Hospitals that do frequent
amnio have lower rates of miscarriages. An interesting
fact to consider is: if you have been advised to have
an amnio because of a raised AFP level, be advised
that there appears to be a link to a significant increase
in miscarriage rates; this is apparently so because
babies with raised AFP have a problem and would have
miscarried at some later stage anyway. If this applies
to you, you should be offered a detailed ultrasound
rather than an amnio for the diagnosis of NTD.
The Procedure itself..
Amnio is often carried out between weeks 16 and 20
by an experienced, well trained Operator. The reason
to wait till this long is because there will be more
amniotic fluid present and the likelihood of needle
puncture on the fetus, the placenta or umbilical cord
is very low. Secondly and more importantly, the presence
of fetal cells in the sac will be higher, increasing
the accuracy of the test.
• You will have to empty your bladder
• Antiseptic will be used to clean your skin
• A needle will be passed into your uterus through
the abdominal wall, and a sample of fluid is drawn
up.
• This is done under direct ultrasound control
so no harm is done to the fetus or placenta
• It takes about 10-15 minutes
• It is usually more uncomfortable then painful
• This sample is immediately sent to the lab
for evaluation; fetal cells are separated from the
liquid to be cultured for chromosomal analysis
What the test reveals:
• The age of the fetus
• The genetic disorders
• The metabolic problems and other birth defects
What happens after the
test?
• Your doctor will check your baby's heartbeat
to ensure all is well
• If you are rhesus negative you will be administered
with an Anti-D injection
• You should go home and rest for 24 hours minimum
• If there is bleeding or fluid leakage, call
your doctor immediately
• You will need to wait for 2-3 weeks for the
results as by that time the cells would have grown
or cultured enough for an analysis
• You can choose to continue with the pregnancy
and keep the baby or opt for a termination; the choice
is yours. ( Termination laws depends on country to
country, so please check with your doctor)
The down side of amnio
Apart from the miscarriage factor, the other worse
thing is the timing; you may be forced to face with
one of life's most crucial decision after such a wait.
By the time the results are back you may be close
to being 20 weeks pregnant. Not only have you grown
more emotionally attached to your unborn child, but
second trimester terminations are more difficult to
perform and are more complicated.
When faced with an amnio?
• Discuss all your options and concerns with
your doctor before you make the appointment for the
test
• Prepare ahead with your partner on all possibilities
and weigh the odds, wherever necessary.
