Fetal Medicine

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Fetal Medicine Specialist
www.bangalorefetalmedicine.com/

Bangalore Fetal Medicine Center
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Fetal medicine is an upcoming branch of
Obstetrics where the fetus is given the primary
care right from screening to diagnosis and
management of a fetal problem
Screening For Down Syndrome Dear Parents to be,
Congratulations! You are stepping into the one
of the most rewarding journey of your life, the
destination of which will be blissful parenthood.
It is indeed our pleasure to support you through
this journey as the Fetal Medicine Unit. The
endeavour of Fetal Medicine is to safeguard the
health and well being of your unborn baby. We
specifically follow the growth and development of
the fetus and look for any problems and suggest
the corrective treatment. Another important
aspect in fetal well being is to look for
chromosomal or genetic problems that may be
inherent and that can profoundly affect the
quality of life after birth. In this context, we
want to educate you about screening for Down
Syndrome.
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What is Down Syndrome? Down Syndrome (DS) is a
chromosomal disorder in which the affected
individual has one extra chromosome in addition
to what is the normally allocated number of
chromosomes. Every human being has 46 chromosomes
arranged in 23 pairs. In people with Down
Syndrome, the chromosome pair number 21 has three
copies instead of two so that the total number of
chromosomes is 47 instead of the normal 46. Each
mans sperm has 23 chromosomes and so does each
womans egg, so that when conception occurs and
the sperm fertilises the egg, a new human being
with a full complement of chromosomes is formed.
Sometimes mistakes occur and lead to what are
described as chromosomal abnormalities. Down
Syndrome is one of the commonest of these. At
conception, instead of one number 21 chromosome
from the father and one from the mother coming
together, a third chromosome creeps in and is
then duplicated in every cell of the babys body.
Down Syndrome, also called Trisomy 21, is the
most common chromosomal abnormality, occurring
approximately once in every 600 births.
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• Why should we test for Downs syndrome?
• Down Syndrome is the most common chromosomal
  abnormality and can have a major social,
  financial and emotional impact on a family. It is
  the commonest cause of global developmental delay
  in children, which is NOT inherited.
• What are the characteristics of Downs syndrome?
• People with Down Syndrome will all have some
  degree of learning difficulty. Many people with
  Downs will go to ordinary schools and lead
  semi-independent lives, but others will need
  full-time care. Certain medical conditions are
  more likely to occur in people with Down
  Syndrome.
• These include
• ? heart defects, which occur in one in three
  children with Downs
• ? digestive tract defects
• ? problems with sight
• ? problems with hearing

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All people with Downs will have certain physical
characteristics, such as eyes that slant upwards
and outwards, a single crease running across the
palm of the hand, low-set ears and small hands.
Babies born today with Down Syndrome can expect
to live between 40 and 60 years on average. Are
you at risk of having a baby with Downs
syndrome? Every mother is at a risk of having a
child with Down Syndrome and this increases with
the mothers age, especially over the age of 35.
However, majority of babies with Downs syndrome
are born to the relatively younger mothers
because there are more number of pregnancies in
women below the age of 35. What can you do to
find out whether or not you baby has Downs
syndrome? The mother can undergo certain tests in
pregnancy. There are two types of test available
screening tests and diagnostic tests. A
screening test estimates the risk of your baby
having Down Syndrome. It only tells you whether
or not you are at particularly high risk of
having a baby with Down Syndrome. This does not
confirm the chromosome status of your baby. A
diagnostic test can give you a definite
diagnosis, but also carries a small risk of
miscarriage.
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What screening tests are available? There are
many different screening tests available. There
are ultrasound tests, blood tests and a
combination of the two. The ultrasound tests
include the nuchal transluscency scan between 11-
14 weeks of pregnancy and the anomaly scan
between 18-20 weeks. In these scans, apart from
the general growth and development, we look for
markers for Down Syndrome in the fetus and
depending on the presence or absence of these
markers, we assess the risk for Down Syndrome The
blood tests include the first trimester test
which measures two hormones in the mother beta
HCG and PAPP-A between 10-14 weeks of pregnancy
or the second trimester triple serum screening in
which three hormones (beta HCG, AFP and uE3) are
measured in the maternal blood between 15 20
weeks. If both ultrasound and blood tests are
done, then the risk assessment obtained from both
can be combined to get a more accurate final risk
assessment. These are the screening tests. They
cant tell you for certain that your baby has or
has not got Down syndrome. A screening test can
help you decide whether or not to have a
diagnostic test.
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The diagnostic test is either a CVS (Chorionic
Villus Sampling) or Amniocentesis which will
confirm the chromosomal status of the fetus and
tell you definitely whether or not your baby has
Down Syndrome. However, these are invasive tests
and they carry a risk of miscarriage. Hence they
are generally offered only if the screening tests
are suggestive of a problem. A cut-off point of 1
in 300 is usually used at BFMC. If your risk is
less than that, you will be described as screen
negative which means that you are unlikely to be
carrying a baby with Downs (but its not
impossible). We will discuss all results with the
parents. However, if any couple consider their
personalized risk assessment high enough to
warrant an invasive test, this will be discussed
and their opinion respected. These tests will
detect many pregnancies affected by Down
syndrome, but they will also identify some
pregnancies as being at risk of Down Syndrome
when, in fact, they are not these are known as
false-positives.
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Eligibility and detection rates
Test Test type Detection rate
First Trimester Double Marker Blood Test Blood test 67
Combined / OSCAR Test (Blood test at 10-13 weeks followed by NT scan at 12-13 weeks) Blood Scan 95
NT Scan 11-136 weeks Scan 80
Second Trimester Triple Blood Test 15-206 weeks Blood test 65
Genetic Sonogram 18-23 weeks Scan 60-70
SEQUENTIAL SCREENING COMBINES ALL THE ABOVE Blood Scan 97-98
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WE HAVE ADDITIONAL INFORMATION LEAFLETS DETAILING
FIRST AND SECOND TRIMESTER SCREENING TESTS. The
Nuchal Translucency (NT) Scan First Trimester
Combined / Oscar Test Second Trimester Triple /
Quadruple Test Contact BFMC, Address 2E, 2nd
Floor, RICH HOMES, 5/1, Richmond Road Bangalore
560 025, India http//bangalorefetalmedicine.com/