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.
Primary amenorrhea is most commonly caused
by genetic or anatomic abnormality.
A genetic abnormality in 50% of cases
and an anatomic abnormality in 15%.
The most common cause is gonadal dysgenesis, most
commonly with Turner syndrome as seen in our case.
This occurs in 1 in 2500
live female births.
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.
The anatomic abnormalities are much less
common, occuring in 15 percent of cases.
And this will include an intact hymen, a
transverse vaginal septum or vaginal agenesis
otherwise known as Mullerian agenesis or
This happens to be the second most
common cause of primary amenorrhea
but it's far less common
than Turner syndrome.
The incidents here is 1 in
5,000 live female births.
Normal female karyotype
in ovarian function
and thus normal external genitalia and
secondary sexual characteristics.
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.
Disruption of the hypothalamic
pituitary ovarian axis
is the most common cause of secondary
amenorrhea after pregnancy.
Hyperprolactinemia accounts for 10-20%
of non pregnancy mediated amenorrhea.
Polycystic ovary syndrome is by far, the most common
hyperandrogenetic cause of secondary amenorrhea.
Asherman syndrome or intrauterine adhesions are
the only uterine cause of secondary amenorrhea.
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.
There is an algorithm for the
evaluation of amenorrhea.
When amenorrhea is present,
particularly secondary amenorrhea,
obtain a serum HCG level to exclude
the presence of pregnancy.
If it is positive and the patient is
pregnant, you have your diagnosis.
On the other hand, if it is negative, a more
substantial endocrine work-up is warranted.
One would start by obtaining a follicle stimulating
hormone, a TSH, a free T4 and a prolactin.
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.
Also, if those are negative, consider obtaining a
pituitary MRI to rule out the presence of a prolactinoma.
When the TSH is abnormal, it
implies underlying thyroid disease
and one then should go on and evaluate
further for thyroid dysfunction.
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.
On the other hand, if the FSH is low or normal, one
should then proceed with progesterone withdrawal testing.
Under these circumstances, the patient is given a
dose of progesterone for a certain number of days.
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.
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.
Also consider a eating disorder or excessive
exercise or stress in the case of patients
who do not undergo progesterone
If there is a history of gynecologic
procedures, also consider hysteroscopy
to evaluate for uterine
adhesions or Asherman syndrome.
If the patient bleeds with progesterone
withdrawal, then consider hyperandrogenism.
Obtain a testosterone level, a dehydorepiandosterone
level and a 17-hydroxypregesterone test.
These patients tend to have
polycystic ovary syndrome
and this is probably the most common cause of
hyperandrogenism leading to secondary amenorrhea.