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Abnormal
Bleeding
Listen to a 10-Minute Audio
Lecture (9 MB MP3 File)
The Menstrual Cycle
Among
women of childbearing age, there is an expected pattern of the menstrual
cycle. The interplay of hormones, receptor sites, growth factors, inhibin,
and activin with the granulosa and thecal cells in the ovary is complex. An
over-simplified version is:
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Responding to low levels
of estrogen, the hypothalamus sends a signal to the anterior pituitary
gland to release follicle stimulating hormone (FSH). In addition to
stimulating ovarian follicular growth, FSH also stimulates the granulosa
cells of the follicle to produce gradually increasing amounts of estrogen.
This estrogen has many effects, including stimulation of the endometrium
glandular epithelium to proliferate (reproduce), creating an environment
that will later prove hospitable for implantation of a fertilized ovum.
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As the estrogen production
accelerates, it begins to inhibit FSH and at the same time stimulates
luteinizing hormone (LH). This leads to a major surge in LH that peaks 12
to 24 hours before ovulation. This surge in LH is accompanied by a
parallel surge in FSH and estrogen.
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After the peak of LH, FSH
and estradiol, continuing secretion of LH causes the granulosa cells to
produce progesterone. In the absence of pregnancy, the progesterone is
produced for about 10 days. Then it and estrogen production rapidly
decline, leading to a significant withdrawal of hormonal support from the
endometrium. This provokes bleeding as the decidualized endometrium is
shed, leaving only the endometrial basal layer of cells.
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Responding to the low
levels of estrogen, the hypothalamus again causes release of FSH from the
anterior pituitary, and the cycle begins again.
Normal Bleeding
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Occurs approximately once
a month (every 26 to 35 days).
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Lasts a limited period of
time (3 to 7 days).
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May be heavy for part of
the period, but usually does not involve passage of clots.
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Often is preceded by
menstrual cramps, bloating and breast tenderness, although not all women
experience these premenstrual symptoms.
Abnormal Uterine Bleeding
Abnormal
bleeding has a number of definitions, the simplest of which is, "all
bleeding that is not normal." Abnormal bleeding includes:
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Too frequent periods (more
often than every 26 days).
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Heavy periods (with
passage of large, egg-sized clots).
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Any bleeding at the wrong
time, including spotting or pink-tinged vaginal discharge
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Any bleeding lasting
longer than 7 days.
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Extremely light periods or
no periods at all
Dysfunctional Uterine
bleeding
Dysfunctional bleeding is another term with varying definitions. Some
consider bleeding dysfunctional if there is any abnormal uterine bleeding in
the absence of uterine pathology or medical illness. Others feel that
drawing such a fine distinction is pointless as many medical illnesses
(polycystic ovary syndrome, hypothyroidism, hyperthyroidism, adrenal
hyperplasia) can create a pattern of bleeding that is clinically
indistinguishable from the traditional "dysfunctional" uterine bleeding.
Many gynecologists use the term abnormal uterine bleeding (AUB) and
dysfunctional uterine bleeding (DUB) interchangeably.
Overview
Any woman
complaining of abnormal vaginal bleeding should be examined. Occasionally,
you will find a laceration of the vagina, a bleeding lesion, or bleeding
from the surface of the cervix due to cervicitis. More commonly, you will
find bleeding from the uterus coming out through the cervical os.
Excluding pregnancy, there
are really only three reasons for abnormal uterine bleeding:
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Mechanical Problems
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Hormonal Problems
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Malignancy
The limited number of
possibilities makes your caring for these patients very simple. If the
bleeding is heavy, obtain a blood count and assess the rate of blood loss to
determine how much margin of safety you have. Someone with a good blood
count (hematocrit) and minimal rate of blood loss (less than a heavy
period), can tolerate this rate of loss for many days to weeks before the
bleeding itself becomes a threat. Determine whether the bleeding is
significant enough to begin iron replacement therapy.
Pregnancy Problems
A variety of pregnancy
problems can cause vaginal bleeding. These include:
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Abortion (threatened,
incomplete, complete, missed, or inevitable)
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Ectopic Pregnancy
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Placental Abruption
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Placenta Previa
If the bleeding patient has
a positive pregnancy test, a careful search should be made for each of these
problems. However, if the pregnancy test is negative, pregnancy-related
bleeding problems are effectively ruled out.
Mechanical Problems
Such
problems as uterine fibroids or polyps are examples of mechanical problems
inside the uterus.
Since mechanical problems
have mechanical solutions, these patients will need surgery of some sort
(Polypectomy, D&C, Hysteroscopy, Hysterectomy, Myomectomy, etc.) to resolve
their problem.
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Polyps visible protruding
from the cervix are usually coming from the cervix and can be easily
twisted off.
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A simple ultrasound scan
can reveal the presence of fibroids and their location. Those fibroids
that are impinging on the endometrial cavity are the most likely to be
responsible for abnormal bleeding.
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Endometrial polyps can be
identified with a fluid-enhanced ultrasound (sonohysterography), a simple
office procedure. They can also be identified during hysteroscopy.
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An endometrial biopsy can
be useful in ruling out malignancy or premalignant changes among women
over age 40. It can also be useful in younger women in identifying the
hormonally confused endometrium of anovulatory bleeding, and will
sometimes pick up a small piece of endometrial polyp.
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Another form of mechanical
problem is an IUD causing abnormal bleeding. These should always be
removed.
Hormonal Problems
Hormonal
causes for abnormal bleeding include anovulation leading to an unstable
uterine lining, breakthrough bleeding associated with birth control pills,
and spotting at midcycle associated with ovulation. Some of these cases will
be related to an underlying medical abnormality, such as polycystic ovary
syndrome, hyper or hypothyroidism, adrenal hyperplasia, and pituitary
adenoma. Rarely, this may be due to a hormone secreting neoplasm of the
ovary.
The solution to all of these
problems is to find and treat those underlying medical abnormalities that
exist, and/or take control of the patient hormonally and insist (through the
use of BCPs) that she have normal, regular periods.
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Thyroid disease can be
ruled out clinically or through laboratory testing (TSH)
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Adrenal hyperplasia can be
ruled out clinically or through laboratory testing (DHEAS, 17
hydroxyprogesterone, ACTH stimulation test)
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Prolactin-secreting
pituitary adenoma can be ruled out clinically or through laboratory
testing (serum prolactin)
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Hormone-secreting ovarian
neoplasms can be ruled out clinically or through laboratory testing
(ultrasound, estradiol, testosterone)
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Anovulation can be
confirmed through the use of endometrial biopsy, although for women under
age 40, biopsy is only infrequently utilized.
If the abnormal bleeding is
light and the patient's blood count good, starting low-dose BCPs at the next
convenient time will usually result in effective control within a month or
two.
If the bleeding is quite
heavy or her blood low, then it is best to have the patient lie still while
you treat her with birth control pills. Some gynecologists have used 4 BCPs
per day initially to stop the bleeding, and then taper down after several
days to three a day, then two a day and then one a day. If you abruptly drop
the dosage, you may provoke a menstrual flow, the very thing you didn't
want.
Alternatively, particularly
for those with intractable anovulatory bleeding, plain estrogen in doses of
2.5 up to 25 mg a day can be effective in promoting endometrial
proliferation, stopping the bleeding. After the bleeding is initially
controlled with estrogen, progesterone is added to stabilize the
endometrium, leading up to a hormonal withdrawal flow a week or two later.
Two drawbacks to this approach are the nausea that frequently accompanies
such large doses of estrogen, and the theoretical risk of thromboembolism
among women exposed to large amounts of estrogen while on bed rest.
Giving iron supplements is a
good idea (FeSO4 325 mg TID PO or its' equivalent) for anyone who is
bleeding heavily.
Malignancy
Abnormal
bleeding can also be a symptom of malignancy, from the vagina, cervix or
uterus.
Cancer of the vagina is
extraordinarily rare and will present with a palpable, visible, bleeding
lesion on the vaginal wall. Cancer of the cervix is more common but a normal
Pap smear and normal exam will effectively rule that out. Should you find a
bleeding lesion in either the vagina or on the cervix, these should be
biopsied.
Factors that increase the
risk for endometrial carcinoma include:
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Increased estrogen
exposure (exogenous or endogenous)
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Diabetes
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Overweight (through
increased conversion of androstenedione to estrone by body fat cells)
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Chronic, untreated
anovulation (many years)
Cancer of the uterus
(endometrial carcinoma) occurs most often in the older population
(post-menopausal) and is virtually unknown in patients under age 35. For
those women with abnormal bleeding over age 40, an endometrial biopsy is a
wise precaution during the evaluation and treatment of abnormal bleeding.
In evaluating
abnormality, you have a number of Diagnostic and Therapeutic Options
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Obtain a Pregnancy test .
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Examine the patient
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Make sure the Pap smear is
up to date.
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Biopsy any visible lesions
of the cervix or vagina.
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Perform an Endometrial
biopsy for women over age 40.
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A Pelvic ultrasound scan
can identify fibroids, and a Sonohysterogram can identify intracavitary
lesions.
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A Blood count can
sometimes be revealing if bleeding has been heavy and prolonged.
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Correct any underlying
medical problems
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Begin OCPs to control
abnormal bleeding due to hormonal causes. Continuous birth control pills
can suppress menstruation completely.
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Depo Provera can be used
to suppress ovulation and menstruation .
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D&C (with or without
hysteroscopy) can remove endometrial polyps
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If bleeding is intractable
and the patient desires to preserve childbearing, consider myomectomy if
submucous fibroids are contributing to the bleeding. Sometimes, this can
be done hysteroscopically.
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If bleeding is intractable
and the patient has completed childbearing, consider balloon or
roller-ball ablation of the endometrium, or even hysterectomy.
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