00:01
Let's now talk about secondary amenorrhea.
00:03
You've had a period once but now it's gone.
00:07
That's secondary amenorrhea as supposed to primary amenorrhea,
which means you never had a menstrual cycle.
00:13
Secondary amenorrhea is defined as no period for 3 cycle lengths or for 3-6 months.
00:19
That's atypical, something has gone wrong and now it's our job to find out what.
00:25
Let's now list the common causes of secondary amenorrhea.
00:30
When you have a low or normal FSH, it can be due to weight loss,
so if you've lost weight in a very quick time your FSH might be quite low.
00:40
If you have an eating disorder such as anorexia or perhaps bolemia, your FSH is low.
00:46
You can have non-specific hypothalamic amenorrhea,
for some reason your hypothalamus just stops firing
and your anterior pituitary does not release gonadotropins.
00:57
A very common cause is chronic anovulation including PCOS.
01:01
For more information about PCOS there's a lectures about that.
01:05
You can have it with hypothyroidism, so that's when your thyroid is not functioning as it should be.
01:11
You can also see a normal or low FSH with Cushing's Syndrome.
01:16
A pituitary tumor or an empty sella or Sheehan syndrome can also cause a low or normal FSH.
01:24
Let's talk a little bit about Sheehan Syndrome.
01:27
Sheehan Syndrome is often tested on a USMLE.
01:31
It usually occurs after a postpartum hemorrhage.
01:35
Postpartum hemorrhage still occur as worldwide and is a number one cause of maternal death.
01:40
In the US, it's less so but with Sheehan Syndrome you get pituitary apoplexy
because of Pituitary loses blood flow during a postpartum hemorrhage.
01:50
These women typically cannot lactate postpartum
and they also lose their axillary hair and they never have return to menses.
01:57
So watch out for this on your exam.
01:59
Let's not talk about high FSH as a cause of secondary amenorrhea.
02:04
This can occur with 46, XX individuals who have primary ovarian insufficiency
or you can have an abnormal karyotype that leads to early cessation of menstrual cycles.
02:15
This is the case with Turner Syndrome patients.
02:18
The majority of cases with Turner Syndrome presents with primary amenorrhea.
02:25
Secondary amenorrhea appears in less than 10% of patients
usually in those who carry up partial deletion of the X chromosome
or have sex chromosome mosaicism.
02:37
You can also have a high prolactin that causes secondary amenorrhea.
02:42
There is another lecture set that you can download to learn more information.
02:46
There are also anatomic causes of secondary amenorrhea.
02:50
This is the case in Asherman Syndrome, you typically see Asherman Syndrome after pregnancy
where some type of dilation and curettage has occurred.
02:59
This can occur as a result of a postpartum hemorrhage or post-abortal.
03:04
These adhesions, because the uterus to actually have adhesions
between the two walls and can obstruct any menstrual flow.
03:11
You can also find secondary amenorrhea in hyperandrogenic states.
03:17
This happens with an ovarian tumor, non-classical congenital adrenal hyperplasia
and also undiagnosed hyperandrogenism.
03:26
There are a lot more causes but we're going to review just the large ones here,
functional hypothalamic amenorrhea is actually the most common cause of secondary amenorrhea.
03:39
You can also have hyperandrogenism and polycystic ovarian syndrome.
03:44
Hyperprolactinemia is third, premature menopause or ovarian insufficiency comes in fourth.
03:51
Asherman's Syndrome is last and then you can have other uncommon causes of secondary amenorrhea.
03:58
But I wouldn’t worry so much about those in your USMLE. Try to remember the above.
04:03
Now, we'll go over what we should do when a patient presents with secondary amenorrhea.
04:09
First, you need to complete a thorough history and physical examination.
04:14
Second, don’t forget to rule out pregnancy as this is a common cause in the reproductive age.
04:20
Third, we need to get an FSH, usually in conjunction with an estradiol,
on the third day of the menstrual cycle and a prolactin.
04:28
A prolactin needs to be taken in the AM and fasting.
04:32
If the FSH is actually equivalent or not higher or not low,
you should suspect an anatomic defect such as Mullerian, a genesis or dsygenesis.
04:44
If the prolactin is high you should do a radiographic evaluation for prolactinoma.
04:51
Unless, there is an obvious cause as to why the prolactin is high.
04:54
Again, there is another lecture that you can listen to that talks about prolactin.
04:59
If the FSH is elevated, this can indicate ovarian failure or ovarian insufficiency.
05:06
This is seen in gonadal dysgenesis.
05:08
If the FSH is low or equivocal, this can mean chronic anovulation
as you see with PCOS and functional hypothalamic amenorrhea.