GSE
Polycystic Ovarian Syndrome (PCOS)
What is Polycystic Ovarian Syndrome (PCOS)?
PCOS is a multi-organ disease which results in
small cysts on the outer layer of the ovaries with a concurrent hormonal
imbalance
An imbalance in hormones that help
regulate the normal development of eggs in the ovaries during each menstrual
cycle
In particular, too many androgens (male
hormones) are produced. It is not
well understood why or how the changes in the hormone levels occur, but these
changes can result in:
Infrequent or no ovulation -
making it more difficult to conceiveInterference
with egg release - androgens play a role in blocking egg releaseHigher than normal risk of miscarriage -
associated with poorer egg quality;
Higher
INSULIN
levels / INSULIN
resistance -
in a majority of women with PCOS
Normal vs. PCOS ovaries during the monthly cycle?
Normally
Each month the ovaries start to ripen a number of
follicles, which are actually cysts, tissue sacs filled with fluid and hormones
(mostly estrogen. ) One or two of these
follicles grow stronger than the others and produce and mature an egg. When
ovulation is triggered by a surge in luteinizing hormone (LH), the egg in the
dominant follicle is released into the fallopian tube en route to the uterus,
where either it is fertilized within 24
hours, or it regresses corpus luteum
producing large
amounts of
Progesterone (and smaller amounts of ESTRADIOL ) to support the pregnancy.
If implantation in the uterus does not occur within 2 weeks the
corpus luteum
usually regresses (via a process called luteolysis) and the uterine lining is shed, seen as menstrual bleeding.
With PCOS
Alterations in hormonal pathways cause the ovaries to form a number of follicles
on the outer layer (cortex)
of the ovary. Follicles (egg-containing sacs
within
the ovaries) normally release one or more eggs during each menstrual cycle -
called ovulation. In PCOS, the eggs in the follicles do not mature and are not
released from the ovaries. Instead, they can form very small cysts inside the ovary.
The ovarian cortex thickens and the egg has difficulty breaking through. No single follicle becomes dominant and ovulation can't occur.
Unlike larger ovarian cysts (follicles > ~
2 cms), PCOS cysts do not cause pain and rupture, but because a woman with PCOS
doesn't ovulate, hormonal cycles are disturbed causing high levels of
estrogens and
androgens Testosterone and
DHEA ), yielding symptoms of
estrogen and
androgen excess.
Minimum criteria for PCOS
diagnosis
Menstrual irregularity - due to infrequent or no ovulation Evidence of
hyperandrogenism -
E.g. hirsutism, acne, male pattern balding, high serum androgen ; PCOS is
the cause of >
70% of cases of androgen excess/secondary
hirsutism Exclusion congenital adrenal hyperplasia
(CAH), androgen -secreting tumors, or hyperPROLACTIN emia
