In this lecture we will be reviewing PCOS or polycystic ovarian syndrome. PCOS affects approximately
5 to 10% of reproductive age women in the US making it most common endocrine disorder in women.
These patients often present with oligoovulation, infertility, and hirsutism. Let's go over the
clinical guidelines to make the diagnosis of PCOS. Patients must demonstrate both clinical and/or
biochemical signs of elevated androgens. They must also have oligoovulation or anovulation.
Remember this is important these diagnoses are a diagnosis of exclusion. There can be other
causes of androgen excess in ovulation that must be ruled out first. In the Rotterdam criteria,
the patient must meet 2 out of 3 of the criteria. She may have elevated androgens either clinically
or biochemically, anovulation, and polycystic ovaries. Again, she has to meet 2 out of 3. Let's
review what the ovary of a PCOS patient would look like on ultrasound. You classically see it
defined or described as pearls on a string. You can see here in this figure that they are closely
related follicles that appear like pearls on a string. This is another image which shows that very
well. If you see this image on your exam, remember PCOS. Let's talk about the evaluation of a
woman with PCOS. It's very similar for a woman with hirsutism. You can read more about hirsutism
in our lecture entitled Hirsutism. Remember to ask women about the age of menarche, description
of their cycles, the duration of their menses or the number of days that they bleed, other
diagnoses, and their OB history. Remember to ask the patient about other family members who
may have hirsutism as we think PCOS may be inherited. Also remember to ask about obesity in
the family. The overwhelming majority of patients with PCOS are obese and she may have a family
history of it. Ask about infertility in both the patient and her family and don't forget high-risk
ethnicities can actually have other disorders such as CAH. There are certain medications that
can also lead to hirsutism. Let's now talk about the long-term risk factors associated with PCOS.
Here you'll see a gross pathologic picture of a patient who's having surgery. This is her ovary
actually filleted open and you can see here the follicles that we just saw on the ultrasound.
However, let's return to the associated problems with PCOS. She has elevated risk of cardiovascular
disease, diabetes later on in life, endometrial carcinoma, psychosocial dysfunction, and infertility
Let's now talk about the evaluation that we would do if we saw a patient with PCOS. We typically
get a serum total testosterone and normal is 20 to 80 ng/dL. DHES is not sensitive or specific
but we usually include it to rule out adrenal processes. There is no uniformly validated and
accepted test for measuring insulin resistance. Most physicians will send a 2-hour glucose
tolerance test to uncover any occult diabetes or insulin resistance that may be present. Also if
the patient knows her menstrual cycle and is in the follicular phase, we will do a morning or a.m.
17-OHP. If it's less than 200, this is normal; however, if it’s between 200 and 400 we will need
to do an ACTH stimulation test to uncover nonclassical CAH. For more information about CAH,
please listen to the lectures associated with that topic. Remember that PCOS is a diagnosis of
exclusion so we also send a TSH to look for thyroid abnormalities that can lead to anovulation.
We also check a prolactin as we know that prolactin can be elevated in PCOS patients. Let's now
talk about the Ferriman-Gallwey scoring system. This is not actually clinically used and I doubt
will be on your exam; however, if you see this in a question think hirsutism. It's not clinically
relevant for us because many patients will wax or shave their hair and then we can't really score
them because it's based on the amount of hair in different positions and locations in the body.
Don’t forget that we need to include CAH or congenital adrenal hyperplasia in our differential
diagnosis. Obviously, these patients would have non-classical CAH with some residual enzyme
activity. For more information, look at the lectures associated with congenital adrenal hyperplasia.
We should also keep in mind that idiopathic hirsutism can be a cause of hirsutism. This was formerly
called familial hirsutism. This is likely due to an excessive activity of the 5-alpha reductase
enzyme in the hair follicle. This is also a diagnosis of exclusion. Our differential diagnosis for
PCOS needs to include Cushing's syndrome. This can be a life-threatening syndrome that we need
to rule out effectively with a 24-hour urine. I discussed more about Cushing's syndrome in the
Hirsutism lecture if you like to find out more. Let's review the management of PCOS. The first
line management is oral contraceptive pills. They work in several ways. In the anterior pituitary,
they decrease LH. LH causes the ovary to make less testosterone and there's less free testosterone.
Also, the liver increases sex hormone binding globulin which increases the binding of free
testosterone. Let's review a checklist. If a patient has a diagnosis of PCOS, then we should
actually give them OCPs in the form of estrogen and progestin. This suppresses LH secretion
and overall will help with hirsutism. Estrogen stimulates sex hormone binding production and
OCPs will decrease adrenal production of DHES. Progestins actually inhibit 5-alpha reductase
activity in the skin, therefore the combined oral contraceptive pill is best. If a patient has
insulin resistance, we should consider using metformin to help overall with this insulin resistance
and potentially a bit of weight loss; however, metformin is not primarily used to induce weight
loss nor is it used for ovulation induction. You may have read that in old literature. That's no
longer accepted. Let's now talk about how we would manage a patient who desires to become pregnant.
Many PCOS patients struggle with infertility. Traditionally, we did ovulation induction with
clomiphene citrate and we know that clomiphene increases the frequency of GnRH pulsatility
and ovarian follicular development. 50% of women will ovulate on 50 mg of Clomid and the average
dose per cycle should not exceed 750 mg; however, current literature suggests that we should
letrozole as a primary agent. Clomiphene citrate can lead to twins or multifetal pregnancies
which have obstetric complications while letrozole, an aromatase inhibitor, has more monofollicular
recruitment. Thank you for listening and good luck on your exam.