All About Secondry Amenorrhea

Secondary Amenorrhea
Lack of menstrual periods in a woman that has had periods previously

Background
Secondary amenorrhea is the absence of menstrual periods for 6 months in a woman who had previously been regular, or for 12 months in a woman who had irregular periods.
This problem is seen in about 1% of women of reproductive age.
Primary amenorrhea is when the woman has never had a period in her life. This page will not discuss primary amenorrhea which is rare. The causes of primary amenorrhea are also quite different from secondary amenorrhea.
A very common cause of secondary amenorrhea in reproductive age women is pregnancy and this should always be excluded by physical exam and laboratory testing for the pregnancy hormone - HCG.

History
A good history can reveal the etiologic diagnosis in up to 85% of cases of amenorrhea.
A detailed menstrual history should be taken.
Any history of galactorrhea (milky discharge from the breasts) is important and indicates the need for a prolactin hormone level to rule out hyperprolactinemia.
A woman who has had hot flashes, breast atrophy and decreased libido along with her amenorrhea may have premature ovarian failure.
Certain medications such as phenothiazines (used for psychiatric disorders) and some narcotics can cause amenorrhea, usually in association with an elevated prolactin and galactorrhea.
A large amount of weight loss or gain can also lead to anovulation - as can stress or extensive exercise.
Anorexia nervosa is often accompanied by secondary amenorrhea.
Both Cushing's disease (over activity of adrenal glands) and hypothyroidism (under-functioning thyroid gland) can cause amenorrhea.
If the patient has a history of severe postpartum hemorrhage (very heavy bleeding after a delivery), she may have pituitary insufficiency from infarction (Sheehan's syndrome).
When amenorrhea follows a D&C (dilation and curettage) one should suspect intrauterine adhesions (Asherman's syndrome), particularly if the procedure was pregnancy related.
Asherman's can also occasionally be seen following other types of uterine surgery such as metroplasty, myomectomy or cesarean section.
Amenorrhea following cervical conization, or other procedures on the cervix (LEEP, etc.) can be due to procedure related cervical stenosis.
Following discontinuation of oral contraception some women will not have periods for up to several months. However, the reported incidence for amenorrhea lasting more than 6 months after the pill is stopped is 0.8% which is essentially the same as the incidence of amenorrhea in the general population. Therefore, amenorrhea of greater than 6 months duration after oral contraceptive use is not related to the pill use.

Physical examination (what the OB/GYN doctor will look for on the exam)
Signs of androgen excess such as hirsutism (excess hair growth) and clitoromegaly (enlargement of the clitoris).
The breast exam may reveal galactorrhea (milky discharge from the breasts).
Estrogen deficiency may be suggested on pelvic exam by a smooth vagina that lacks the normal rugae (wrinkles) and a dry endocervix with no mucous.

Workup after history and physical (what the doctor will do next)
If the history and physical exam are suggestive of a certain etiology then the initial laboratory or radiographic workup can be tailored appropriately.
For example, a 32 year old woman who has previously had regular menses presents with 10 months of amenorrhea following a curettage for heavy bleeding associated with an incomplete abortion. She has no signs or symptoms that suggest ovarian failure or thyroid disease. There is no galactorrhea and she uses no medications or street drugs. She most likely has intrauterine adhesions causing her amenorrhea. A reasonable approach to this patient would be an hCG level to rule out pregnancy, an FSH level to demonstrate the presence or absence of ovarian function, and then a hysterosalpingogram or hysteroscopy if these first 2 tests are normal. One could also do the entire diagnostic workup as recommended for patients without any etiology apparent. However, for the sake of efficiency and cost-effectiveness, the workup can sometimes be more directed.
Some patients will not demonstrate any obvious etiology for their amenorrhea on history and physical exam. These patients can be worked up in a logical manner using a stepwise approach. Diagnostic approaches may vary, however, differences between them pertain mainly to the order in which tests are performed.
There are several ways that a workup for secondary amenorrhea can be approached. One reasonable diagnostic approach is described here. If your doctor did things differently, that doesn't mean that he or she was wrong or that this approach is wrong. Every case should be treated individually.
In the approach described here, the first tests to perform after pregnancy is ruled out are a progesterone withdrawal test as well as a TSH (thyroid stimulating hormone) and prolactin level.

Thyroid function
Both hypothyroidism and hyperprolactinemia can cause primary or secondary amenorrhea. If these entities are discovered, appropriate therapy should result in resumption of regular menstrual periods.

Progestational challenge (progesterone withdrawal test)
The progestational challenge test is performed by giving oral medroxyprogesterone acetate 10 mg daily for 7-10 days or progesterone in oil 100-200 mg intramuscularly. A positive response is any bleeding more than light spotting that occurs within 2 weeks after the progestin is given. This bleeding will usually occur 2-7 days after the progestin is finished. Withdrawal bleeding will usually be seen if the patient's estradiol level is 40 pg/ml or more.
If the patient experiences bleeding after the progestin she has estrogen present but is not ovulating. If no withdrawal bleeding occurs, either the patient has very low estrogen levels or there is a problem with the outflow tract such as uterine synechiae (adhesions) or cervical stenosis (scarring).