Primary Amenorrhea
Lisa L. Wil= lett, MD
January 200=
7
Definitions
Primary Amenorrhea – normal secondary sexual characteristics but no menarche by age 16, OR no secondary sexual characteristics and no menarche by age 14.
Secondary Amenorrhea – absence of menses for 3 m= onths in women with previously normal menstruation, OR for 9 months in women with previous oligomenorrhea.
Secondary amenorrhea is more common than primary.
Case 1.
18 year old female, going to college, has amenorrhea.<= span style=3D'mso-spacerun:yes'> She has never had a period. She ran track in high school and a= lways blamed it on that. She has no= rmal secondary sexual characteristics (breasts, pubic hair). She denies sexual activity. What is the appropriate evaluation= ?
By definition, she has primary amenorrhea. Causes of primary amenorrhea are evaluated in the context of the presence or absence of secondary sexual characteristics. If a patient= has normal secondary sexual characteristics (including pubic hair), then you can assume normal hypothalamic-pituitary-ovarian hormonal axis development. Causes of the amenorrhea are, ther= efore, anatomic and related to the uterus.
In this case, you should perform an ultrasound or MRI = confirming a uterus is present.
If there is a uterus, consider that she has an = outflow obstruction, from either an imperforate hymen or transverse vaginal septum. They usually have cyc= lic abdominal pain from blood accumulation.&nb= sp; If the outflow tract is patent, then proceed with a secondary amenor= rhea evaluation.
If there is not a uterus, or it’s abnorma= l, consider a congenital problem (Mullerian agenesis, an absence of a vagina and abnormal uterine development, but embryonic activation of the antimullerian hormone.) The n= ext step is genetics referral for karyotype analysis.
As with secon=
dary amenorrhea, ALWAYS check a pregnancy test.
Case 2.
18 year old female, going to college, has amenorrhea.<= span style=3D'mso-spacerun:yes'> She has never had a period. She ran track in high school and a= lways blamed it on that. She has ne= ver developed secondary sexual characteristics (breasts, pubic hair). She denies sexual activity. What is the appropriate evaluation= ?
This is more complicated, and fortunately less common.= Her hormone axis has not developed properly, and you must find where the problem is in the axis. First check an FSH and LH level.
If FSH and LH are low (< 5 IU per L), she ha= s hypogonadotropic hypogonadism (ie, the pituitary isn’t working). The most common cause in primary amenorrhea is constitutional delay of growth and puberty. The other cause is Kallmann syndro= me (which is associated with anosmia also).
There are many other causes of hypogonadotrpic hypogon= adism, which are more commonly in secondary amenorrhea (anorexia, chronic illness, excessive exercise, excessive weight loss) and will be discussed in that to= pic.
If FSH and LH are high (FSH > 20 IU per L, L= H > 40 IU per L), then she has hypergonadotropic hypogonadism, which imp= lies an ovary problem, by premature ovarian failure (idiopathic, chemo or radiat= ion, mumps oophoritis) or gonadal dysgenesis.&n= bsp; This is Turner’s syndrome, 45 XO with web neck, short stature, widely spaced nipples and short stature.&n= bsp; Mosaicism can occur in 25% of patients with Turner’s syndrome = and have a normal phenotype, so chromosome studies (karyotyping) should still be done.
Examples:
1. 20 yo= female, never had a cycle, with normal secondary sexual characteristics.
U/S or MRI: no uterus.
She likely has a congenital problem (Mullerian agenesis). Refer to genetics = for karyotype analysis.
2. 20 yo= female, never had a cycle, with normal secondary sexual characteristics. She has cy= clic abdomen pain but never bleeds.
U/S or MRI: uterus present.
She likely has an outflow obstruction, from eit= her an imperforate hymen or transverse vaginal septum. Refer to gyn.
3. 20 yo= female, never had a cycle, with no breast or pubic hair development.
FSH and LH undetectable. Hypogonadotropic hypogonad= ism (Kallman syndrome or other causes like anorexia, chronic illness, excessive exercise, excessive weight loss. See secondary amenorrhea).
4. 20 yo female, never had a cycle, with no breast or = pubic hair development.
FSH and LH elevated. Hypergonadotropic hypogonadism= , caused by an ovary problem, like by premature ovarian failure or gonadal dysgenesis (Turner’s syndrome).
Ref: Mas= ter-Hunter, Am Fam Physician 2006;73:1374-82