Antenatal Tests
Antenatal tests can be divided into 2 types of categories
Screening Tests
Diagnostic or Invasive TestsPRENATAL SCREENING TESTS
Nuchel Transluency (NT) SCAN
The nuchal transluency is the measurement of thickness
of the fluid-filled space at the back of the baby's neck.
It is mainly to detect the down syndrome. It is also proving
useful to detect abnormalities related to the heart of
the foetus. The test is performed during 12-13 weeks of pregnancy using
an ultrasound technology.
Bio chemical Screening (NT plus)
In this screening, nuchel Transluency scan results together
with the levels of 2 placental proteins(PAPP-A and free
ßhcg)present in maternal blood, are assesed to get an
estimate of the risk of the chromosome abnormality. Combined
with NT it can detect up to 80-90 percent of babies with
down syndrome. However, it is a new option and may not
be available every where.
Triple Test or Maternal Serum Screening
This test measures level of alpha-fetaprotein, (hcg) and
unconjugated estriol(a form of estrogen produced by the
placenta) by analyzing the blood sample taken from a pregnant
woman.This test is capable of detecting 80% of neural
tube defects and 60% of down Syndrome cases.
DIAGNOSTIC OR INVASIVE TESTSThese tests are performed when
- women is over 35 years of age
- a screening test indicating an increased risk
- previous child or pregnancy with chromomal abnormality
- a family history of genetic abnormality
Chrionic Villus Sampling(CVS)
This test is performed between 10-12 weeks of gestation.
there are two ways of performing this test. A catheter
is passed through cervix or a needle is inserted through
the abdomen to to obtain a sample of chrionic villus tissue(the
tissue that will eventually become placenta). The risk
of miscarriage associated with this procedure is less
than 1 percent. Amniocentesis This test is so far considered to be most accurate test in detecting
down syndrome and other chromosomal abnormalities.
It is mainly performed during 15-16 weeks of pregnancy.
A fine needle is inserted through abdomen to withdraw
small amount of amniotic fluid for analysis. This test is
performed under ultrasound guidance. The risk of miscarriage
associated is less than 1 percent.
 Know well before any intake of medicines during pregnancy
Pregnancy and Diet: a healthy eating plan
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