| To ensure the
most accurate
results we use
PGD for Gender
Selection which
involves the
genetic
investigation of
early stage
embryos that
have been
produced through
in-vitro
fertilization
(IVF). PGD
allows us to
determine the
sex of
individual
embryos (female
or male) and
their
chromosomal
make-up (whether
the embryo is
chromosomally
normal, or, for
example, has
Downs Syndrome).
PGD is more than
99% accurate so
is the perfect
tool for
patients wishing
to choose the
gender of their
baby.
The PGD
process
Embryos created
in an IVF cycle
are cultured in
the laboratory
for 3 days when
they will have
developed
approximately 8
cells. Embryos
with normal
development on
Day 3 will have
one or two cells
removed for
testing. This is
performed by
placing the
embryo under a
powerful
microscope and
using a Laser to
make a small cut
in the zona
pellucida, (a
tough outer
membrane holding
the embryo
together).
Depending on the
health and size
of the embryo,
one or two cells
are taken out.
The cut then
snaps shut so no
cells can fall
out
accidentally. |
 |
PGD is a safe
and reliable
method of Gender
Selection
There is no
evidence that
PGD leads to an
increase in
birth defects or
chromosomal
disorders. PGD
is done before
the embryo’s
genetic material
becomes ‘active’
when the cells
inside the
embryo are still
all identical
and each cell is
still capable of
becoming any
part of a baby.
Removal of one
or two cells
from the early
embryo does not
alter the
ability of that
embryo to
develop into a
complete, normal
pregnancy.
The Science
Gender is
determined by
our sex
chromosomes. PGD
testing is
different to
most genetic
testing, since
it is performed
on only one or
two embryonic
cells and must
be completed
within 48 hours
to allow embryo
transfer by Day
5. Since
standard
chromosome
analysis takes
several days, a
different method
called
Fluorescence
In-Situ
Hybridization
(FISH) is
performed that
can be completed
within 4 to 6
hours.
Each chromosome
has unique areas
of DNA present
only on that
chromosome. A
small DNA probe
is used to
recognize these
unique patterns
and lights up
when it attaches
to the
chromosome. Each
probe shines
light in a
different color,
allowing several
chromosomes to
be tested at the
same time. This
technique is
known as FISH.
FISH probes for
X and Y are used
to determine the
gender of each
embryo. A normal
cell should show
2 FISH signals
(or lights) for
the numbered
chromosome, and
either 2 X
signals for a
female or 1 X
and 1 Y signal
for a male.
Choosing which
embryos to
transfer
We only transfer
embryos that
have a normal
test result and
appearance. The
combination of
normal genetics
with normal
physical
appearance gives
each embryo the
best chance of
developing into
a healthy
pregnancy.
Our
Embryologists
grade the
embryos based on
the uniform size
of the different
cells, the
number of cell
fragments
present, as well
as other
criteria
reflecting the
physical
appearance of
the embryo.
Embryos that do
not have at
least 5 cells on
day 3 or embryos
that are given a
poor score
rarely go on to
successfully
implant.
Cryopreservation
Decisions about
which embryos to
transfer are
made by Dr Wiwat
and our Director
of Embryology
Mrs. Tida. You
also have the
option of
storing the
remaining
embryos using
Cryopreservation
in case a
subsequent
transfer cycle
is required. And
of course you
can also
'balance' your
family with an
embryo of the
opposite sex if
you have a
successful
pregnancy and
want another
child later on.
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