00:01
Primary amenorrhea is the absence of menses
at age 15 in the presence of normal growth
and secondary sexual characteristics
as occured in this case.
00:11
Primary amenorrhea is most commonly caused
by genetic or anatomic abnormality.
00:17
A genetic abnormality in 50% of cases
and an anatomic abnormality in 15%.
00:23
The most common cause is gonadal dysgenesis, most
commonly with Turner syndrome as seen in our case.
00:30
This occurs in 1 in 2500
live female births.
00:36
Treat these patients with exogenous
estrogen therapy with cyclic progestin
to prevent endometrial hyperplasia and continue
this until age 51, the average age of menopause.
00:48
The anatomic abnormalities are much less
common, occuring in 15 percent of cases.
00:53
And this will include an intact hymen, a
transverse vaginal septum or vaginal agenesis
otherwise known as Mullerian agenesis or
Mayer-Rokitansky-Kuster-Hauser syndrome.
01:06
This happens to be the second most
common cause of primary amenorrhea
but it's far less common
than Turner syndrome.
01:13
The incidents here is 1 in
5,000 live female births.
01:17
Normal female karyotype
in ovarian function
and thus normal external genitalia and
secondary sexual characteristics.
01:28
Secondary amenorrhea is the absence of
menses for more than 3 months in women
who previously had regular menstrual cycles or
6 months in women who have irregular menses.
01:40
Disruption of the hypothalamic
pituitary ovarian axis
is the most common cause of secondary
amenorrhea after pregnancy.
01:48
Hyperprolactinemia accounts for 10-20%
of non pregnancy mediated amenorrhea.
01:55
Polycystic ovary syndrome is by far, the most common
hyperandrogenetic cause of secondary amenorrhea.
02:03
Asherman syndrome or intrauterine adhesions are
the only uterine cause of secondary amenorrhea.
02:10
Asherman syndrome should be suspected in those patients
who had prior dilatation and curettage of the uteruses
with a maybe some form of injury where fibrous
adhesions have formed and obliterated
the central core of the uterus
preventing adequate menses.
02:29
There is an algorithm for the
evaluation of amenorrhea.
02:33
When amenorrhea is present,
particularly secondary amenorrhea,
obtain a serum HCG level to exclude
the presence of pregnancy.
02:41
If it is positive and the patient is
pregnant, you have your diagnosis.
02:46
On the other hand, if it is negative, a more
substantial endocrine work-up is warranted.
02:51
One would start by obtaining a follicle stimulating
hormone, a TSH, a free T4 and a prolactin.
02:59
Starting with prolactin, if prolactin is elevated,
always repeat it to confirm it's positivity
and review the list of medications
that the patient is on.
03:08
Also, if those are negative, consider obtaining a
pituitary MRI to rule out the presence of a prolactinoma.
03:18
When the TSH is abnormal, it
implies underlying thyroid disease
and one then should go on and evaluate
further for thyroid dysfunction.
03:26
With regards to FSH, if the FSH is elevated,
one should then go on and obtain a karyotype
and consider primary ovarian insufficiency as was
the case with our patient with Turner syndrome.
03:40
On the other hand, if the FSH is low or normal, one
should then proceed with progesterone withdrawal testing.
03:48
Under these circumstances, the patient is given a
dose of progesterone for a certain number of days.
03:53
When the progesterone is stopped, when the
patient stops taking the progesterone,
they essentially withdraw from it and
one hopes to invoke a withdrawal bleed.
04:04
However, if no bleeding is present
with progesterone withdrawal
and the patient has headaches
or temporal vision loss,
obtain a head MRI again to rule out
pituitary course for the amenorrhea.
04:18
Also consider a eating disorder or excessive
exercise or stress in the case of patients
who do not undergo progesterone
withdrawal bleeding.
04:28
If there is a history of gynecologic
procedures, also consider hysteroscopy
to evaluate for uterine
adhesions or Asherman syndrome.
04:39
If the patient bleeds with progesterone
withdrawal, then consider hyperandrogenism.
04:44
Obtain a testosterone level, a dehydorepiandosterone
level and a 17-hydroxypregesterone test.
04:51
These patients tend to have
polycystic ovary syndrome
and this is probably the most common cause of
hyperandrogenism leading to secondary amenorrhea.