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Polycystic Ovarian Syndrome (PCOS)
Polycystic
ovarian syndrome is a condition in which there is a hormonal
imbalance within the ovaries. It is a complex condition. In
PCOS, the ovaries are bigger than average, and the outer surface
of the ovary has an abnormally large number of smaller follicles
(these are the sacs of fluid which grow around the egg in
response to the stimulating hormones from the brain). In PCO
these follicles remain immature, which means that ovulation
rarely happens and so the woman is less fertile.
Women
who have PCOS may have the following problems:
1)
infertility due to lack of ovulation
2) excessive body hair growth (hirsutism) due to imbalance
between hormones
3) irregular menstrual cycles and heavy bleeding (cycles which
are either less than 21 days or more than 35 days apart) due
to lack of ovulation
4) acne
5) obesity.
Some
women with PCOS may have a higher than normal miscarriage
rate if they become pregnant.
While
it is not known if women are born with this condition, PCO
seems to run in families. Interestingly, when PCOS is passed
down the man’s side of the family, the men are not infertile,
but they do have a tendency to go bald in early life, before
the age of 30. Ongoing research is trying to clarify whether
there is a clearly identifiable gene for PCOS. Women are also
at a risk if they are overweight. Maintaining weight or body
mass index (BMI) below a critical threshold is probably very
important as weight loss improves hormonal abnormalities and
improves the likelihood of ovulation and thus pregnancy.
The
diagnosis of PCOS is made primarily on the woman's presenting
history and examination. The diagnosis can be confirmed on
ultrasound or by measuring the woman's hormonal levels. If
the ultrasound and the blood tests are normal it does not
mean that the woman does not have the condition. However,
it has also been found that women who do not have problems
with their periods or have excessive hair growth can have
ovaries, which on ultrasound have the appearance of being
polycystic.
The
treatment of a woman with PCOS will depend on the presenting
problems. If a woman presents with irregular heavy bleeding,
the oral contraceptive pill (OCP) is the treatment of choice,
both to regulate the cycle and to prevent over growth of the
endometrium (lining of the womb). Progesterone can also be
given to replace what is not being produced monthly. If hirsutism
(excessive hair growth) is the problem it can be treated using
the OCP as well as with drugs that act against testosterone.
If these drugs are used it is most important that the woman
use a reliable form of contraception as they may cause genital
abnormalities in a male baby if the woman becomes pregnant.
If infertility is the problem then clomiphene citrate (Clomid)
given orally for 5 days early in the menstrual cycle may induce
ovulation. Ovulation can be induced in 80% of women using
Clomid and pregnancy rates approach those seen in the normal
population (20-25% per month) provided that there are no other
factors affecting fertility. The most common side effect with
Clomid is hot flushes. The multiple pregnancy rate with Clomid
is 5% and the majority of these multiple pregnancies are twin
pregnancies.
If
Clomid fails to induce ovulation at maximal doses or if the
woman has tried Clomid for up to 6 cycles in which she has
ovulated but has not become pregnant, follicle-stimulating
hormone (FSH) at low doses may be given. Prior to using these
drugs the treating doctor will want to (if she/he has not
already done so) make sure that the woman's Fallopian tubes
are open and that her pelvis is normal. These drugs are given
by injection and when the woman uses these drugs she needs
to be monitored using blood tests and ultrasounds to make
sure that the drugs are not causing her to develop too many
eggs. The aim when these drugs are used is to cause only one
egg to develop (similar to in a natural cycle).
Nevertheless,
the multiple pregnancy rate may be 20-30% with 80% of these
multiple pregnancies being twin pregnancies.
Weight
loss is also of paramount importance. The disease process
may be reversed with loss of weight and there is also evidence
that the higher miscarriage rate may decrease to that in the
general population with weight loss. A dietician may be required.
PCOS can lead to a resistance to insulin, leading to the body
producing excessively high levels in an attempt to compensate.
This higher level of insulin is known to cause abnormal cholesterol
and lipid levels, obesity and an increased likelihood of diabetes.
Metformin is a type of drug known as an “insulin-sensitising
agent” which lowers the blood sugar level, in turn reducing
the excessively high insulin. There have been studies carried
out to date, which show the use of insulin-sensitising drugs
as a treatment for PCOS. These suggest that it may well be
useful in several areas: helping weight reduction, normalizing
blood cholesterol and improving irregular periods (70%) leading
to ovulation. One study looking at ovulation in particular
found that compared to no treatment, 34% of women ovulated
taking Metformin (compared to 4% who did not receive it) and
when this was combined with clomiphene it was as high as 90%
(compared to 8% who only received clomiphene). The most common
side effects during treatment on Metformin are diarrhoea,
nausea, vomiting and abdominal bloating.
An
operation called ovarian drilling, performed by laparoscopy,
can also be used to treat women with PCOS. This operation
is usually reserved for women who want to be pregnant, and
who have not ovulated on Clomid. In these women it may be
used as an alternative to HMG or FSH. During this procedure
the ovary is cauterized by drilling into it in a number of
spots. We do not know exactly why this procedure works. If
the operation is successful the effect may be long lasting.
In
a small number of women, PCOS can be a very severe disease
in that it can lead to the development of diabetes with all
its complications. If the doctor suspects that the woman has
this type of illness, she may need to undergo testing to make
sure that she is not currently a diabetic. If diabetes is
diagnosed weight loss, diet and the possible use of tablets
may be necessary.
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