Secondary Amenorrhea - Causes
What is Secondary Amenorrhea?
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.
Primary amenorrhea is when the woman has never had a period in her life. Primary amenorrhea is rare and will not be discussed here. The causes of primary amenorrhea are quite different from secondary amenorrhea.
How Common is Secondary Amenorrhea?
- This problem is seen in about 1% of women of reproductive age
Secondary Amenorrhea is a Symptom
- Secondary amenorrhea is a symptom that can be caused by many pathological states
Importance of Recording a Menstrual/Fertility History
- A good history can reveal the etiologic diagnosis in up to 85% of cases of amenorrhea
- A detailed menstrual history should be taken.
Possible Causes of 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.
Medications and Narcotics
Certain medications such as phenothiazines (used for psychiatric disorders) and some narcotics can cause amenorrhea, usually in association with an elevated prolactin and galactorrhea.
No Periods After Discontinuation of the Pill
Following discontinuation of oral contraception some women will not have periods for up to several months. However, the incidence for amenorrhea lasting more than 6 months after the pill is stopped is 0.8% which is the same as the incidence of amenorrhea in the general population.
Therefore, amenorrhea of greater than 6 months duration after oral contraceptive use is stopped is not related to the pill use.
Medical Conditions that Cause Secondary Amenorrhea
Any history of galactorrhea (milky discharge from the breasts) is important and indicates the need for a prolactin hormone level to rule out hyperprolactinemia. Appropriate therapy should result in resumption of regular menstrual periods.
Over activity of adrenal glands can cause amenorrhea.
An under-functioning thyroid gland can cause amenorrhea. Appropriate therapy should result in resumption of regular periods.
Premature Ovarian Failure (Premature Menopause)
A woman who has had hot flashes, breast atrophy and decreased libido along with her amenorrhea may have premature ovarian failure.
A large amount of weight loss or gain, recent stress or extensive exercise can lead to anovulation - a lack of normal, regular ovulation.
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 (scarring).
Anorexia nervosa is often accompanied by secondary 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). This is a very uncommon condition.
Stepwise Diagnostic Approach and Treatment
A stepwise diagnostic evaluation of secondary amenorrhea should lead to the correct diagnosis.