|
IN VITRO FERTLISATION (IVF)
This method first came into practice in 1977, when two
doctors, one a leading obstetrician and gynaecologist and the
other a physiologist achieved the first successful 'test-tube'
implantation. Louise Brown, the result of this extensive
procedure, was born nine months later after a normal, healthy
pregnancy with the treatment of infertility being radically
revolutionised.
This procedure normally has a good success rate, but shouldn't
be viewed as a 'cure-all' for infertility.
What is involved in the process of IVF?
The woman concerned is given drugs to stimulate her ovaries,
in order to achieve multiple ovulation. After establishing the
precise date of ripening, the eggs are then removed, via the
abdomen using a laparascope. Another method, would be to
approach the ovary from the inside of the pelvis, thus avoiding
the necessity for an abdominal incision and general anaesthetic.
During this procedure, usually more than one egg is removed for
fertilisation, to save repeating the operation in the case of
failure. However it is best to bear in mind that the procedure
may have to be repeated for a few cycles before the 'healthiest'
of eggs are gathered, therefore the latter technique would also
have the advantage of fewer surgical incisions to the abdomen.
The ripe eggs are then placed in a flat container, where they
are incubated for up to 24 hours and continuously checked to
ensure that they are healthy and fully-developed. After the
given time, sperm which has been 'washed' to remove any traces
of degenerating produce, is then introduced. If the conditions
are favourable, fertilisation will then take place. However, if
fertilisation does not occur, the egg will be studied, and
wherever possible an explanation is offered to the couple
concerned. Sometimes the cause will be evident, and further
steps will be taken to overcome the problem during the next
treatment attempt.
Embryo transfer:
On division, the embryo is placed in a tiny drop of fluid, which
is transferred to a thin plastic tube. During this stage it is
important that these events occur as quickly and as gently as
possible, so as to prevent the embryo being adversely affected.
While this is taking place, the women concerned will lie on her
back with her feet placed in stirrups. The doctor will then
insert a speculum so as to expose the cervix, and check the
position and size of the uterus, so as to establish the best
method for passing the tube, containing the embryo into it. Any
excess fluid surrounding the cervix will also be removed, so as
to ensure that none will stick to the embryo, thus preventing
implantation.
The tube containing the embryo will then be passed through the
vagina, cervix and a short distance into the uterus, where it
will be released. The exact measurement of placement will be
established during an ultrasound scan done during a prior visit.
Once this is complete, the catheter is gently withdrawn, and
inspected in the laboratory to ensure that the embryo has indeed
been 'placed' into the patient.
What is the success rate, and how safe is IVF?
It must be considered that there is a high failure rate with
success being achieved in less than one-third of couples who
become involved in the treatment and less so in women who are
over the age of 38 years. Multiple pregnancy is yet another area
that should be taken into account, as it is common practice for
three fertilised cells to be inserted at one given time in order
to be sure of at least one success.
The potential misfortune of babies being born with certain birth
defects, arising from embryo handling is highly unlikely, as of
the several thousand IVF pregnancies, only two abnormal cases
have been reported, and it is expected that even this incidence
will be reduced as embryo and foetal monitoring techniques
improve.
|
