An abnormal uterine cavity can result in infertility. Sperm that
enters the uterine cavity through the cervical mucus must then
traverse this cavity and enter the fallopian tube to reach the
egg. These structures should be confirmed to be normal early in
the infertility evaluation. The most popular, safest and most
cost effective way of doing this appears to be the hysterosalpingogram
The HSG is a radiologic test performed under fluoroscopy by a
radiologist and/or possibly by the infertility specialist. The
test requires that a radioopaque distending media is used, which
is seen by xray on film and fluoroscopy. During the performance
of the test, the physicians can watch a monitor which normally
shows the dye entering and filling the uterine cavity and then
entering and spilling from the fallopian tubes.
There are two major types of HSG distending media, water soluble
dye and oil based dye. Essentially, the water based dye is more
rapidly absorbed yet is associated with a higher incidence of
muscle spasm and discomfort. The oil based dye is much more slowly
absorbed over possibly days to weeks (versus minutes to hours
for the water based equivalent) and is associated with more serious
complications (including granulomas) that are potentially fatal
(oil emboli) if infused directly into the blood stream under pressure
through an open channel.
There are anecdotal reports of increased pregnancy following HSG,
possibly due to the opening of the tubes with the dye (commonly
referred to as "blowing out the tubes"). The use of
oil based media is associated with a somewhat higher subsequent
pregnancy rate than water based HSGs. The HSG currently remains
a diagnostic and not a therapeutic test.
The oil based dye has many supporters, and yet, I prefer use of
the water based dye since there are less complications of a serious
nature. Also, if oil based dye is used then ideally (for the quality
of the study) the patient must return to the radiologic suite
the day after initial injection for another xray of the pelvis
to determine the location of the dye (to see whether there is
free spillage or loculation of dye), which is inconvenient.
About 3-6 milliliters is normally required to fill the uterus
and tubes. Image intensification with fluoroscopy allows direct
viewing of the procedure on a monitor and limits the number of
films that must be taken (consequently reducing the total amount
of radiation used).
I recommend that an antibiotic, Doxycycline (when there is no
history of allergy to Tetracycline or Doxycycline), be given around
the time of the HSG since the flushing of these spaces (cavity
and tubes) can reactivate a dormant infection to result in a clinically
apparent infection (pelvic inflammatory disease). Research has
indicated that there is up to an 11% risk of developing pelvic
inflammatory disease (PID) in dilated or distally blocked tubes
following an HSG if no antibiotics are used, a 3% risk of serious
infection after HSG if there is a history suggestive of prior
tubal infection or damage, and less than a 1% chance of infection
if the patient is pretreated with Doxycycline regardless of history
or findings of distal tubal disease. I give Doxycycline as 100
mg by mouth twice a day for a total of 4 tablets starting the
evening prior to the test.
With water based dye, the patient often experiences what appears
to be a large uterine cramp or contraction. This is thought to
be a reaction of the uterine muscles to the rapid expansion and
decompression of the uterine cavity with dye. The discomfort associated
with this cramp may be largely prevented or relieved by taking
a nonsteroidal antiinflamatory agent like Motrin or Alleve 30-60
minutes prior to the test.
* (1) Ashermann's syndrome
Ashermann's syndrome is the occlusion or obliteration of the uterine
cavity due to damage to the endometrium (lining of the cavity).
This is not common but is important to recognize if present. When
the endometrium is destroyed beyond a certain depth (believed
to be the basalis level which is the level that promotes subsequent
growth) in the context of hypoestrogenism (a low circulating estrogen
concentration) then permanent scar tissue can form within the
cavity. Clinical situations that increase the chance of Ashermann's
- overzealous dilatation and curettage (especially for a missed
abortion, postpartum bleeding, or septic abortion),
- intrauterine surgery to remove fibroid tumors or uterine structural
defects (septum, bicornuate uterus, large polyps),
- infections related to IUD use (or the placement of any foreign
object within the uterine cavity),
- some uncommon infections in the uterus (Tuberculosis, Schistosomiasis),
- radium insertion into the uterus for the treatment of a gynecologic
The finding on HSG exam for Ashermann's Syndrome is intrauterine
filling defects These are irregular areas within the normally
triangular shaped cavity where the distending media is excluded
due to the presence of the adhesions (scar tissue). Thin adhesions
may be primarily composed of fibroconnective tissue with little
blood supply. The thicker the adhesions, the greater the likelihood
that they are vascular and possibly also partially muscular. Vascular
and muscular adhesions are much more difficult to repair and seemingly
pose a greater problem for fertility.
Repair of intrauterine adhesions is most easily and safely performed
by hysteroscopy. Operating scissors can be used through some hysteroscopes
but tend to be flimsy for any but very thin filmy adhesions. A
type of operating hysteroscope called a resectoscope allows the
surgeon to apply electrical current through a monopolar cutting
instrument attached as the operating element of the hysteroscope
and lysis (cutting) of the adhesions can then be performed. In
more complex cases of adhesions, repeated procedures may be required.
After each hysteroscopic repair in which cautery is used or extensive
lysis of adhesions is accomplished, the patient is typically placed
on higher dose estrogen replacement (say, Premarin 1.25 or 2.5
mg by mouth each day for 30-60 days, with a Provera withdrawal
flow brought on at the end of this time) to promote the regrowth
of endometrium (lining) over the repaired sites. Occasionally,
a stent (such as an IUD or pediatric foley balloon) is also placed
within the cavity to keep the sides of the uterus apart during
the repair period.
For mild to moderate adhesions, you might expect a 60-80% chance
of successful pregnancy after repair. For more extensive adhesions
the chance of a successful pregnancy is lower. If a pregnancy
does occur after repair of Ashermann's Syndrome there is a greater
chance of preterm labor and delivery (delivery of a premature
baby), placenta accreta (where the placenta invades the uterine
wall into the muscular component of the wall and becomes difficult
to impossible to remove) and postpartum hemorrhage (heavy bleeding
after the delivery of a baby).
* (2) Uterine fibroids
Uterine fibroids, known as leiomyoma uteri, are tumors of the
smooth muscle of the uterus. Fibroid tumors of the uterus are
common, with about 75% (3 of 4) of uterine specimens removed at
the time of abdominal hysterectomy having fibroids (many are quite
small) and about 15-20% of hysterectomies are performed for problems
The uterine wall is primarily composed of smooth muscle (the myometrium).
A uterine fibroid is thought to originate as a gene mutation within
one of these myometrial (smooth muscle) cells that leads to the
progressive loss of its own growth regulation. Each fibroid tumor
grows from a single progenitor cell (each tumor arises from one
single cell) and all the cells within a particular fibroid contain
the same abnormal DNA that favors growth. Different fibroid tumor
originate from different muscle cells, each with their own genetic
(DNA) abnormality so that each tumor may grow at its own rate
(some faster and some slower). Fibroid tumors are not malignant
(cancer) yet there is an uncommon cancer called "leiomyosarcoma"
that is composed of malignant smooth muscle cells. It is not clear
whether these cancers develop from benign fibroids or whether
they arise independently.
The role of uterine fibroids in reproduction is usually not clear.
If the fibroid is presenting (bulging) into the uterine cavity
(submucosal) then it may obstruct one of the fallopian tube entrances
or it may present a mechanical or other barrier to implantation.
If the fibroid is throughout an entire wall of the uterus, then
it might interfere with the blood supply to the uterine structures
around it or an embryo implanting near it. If the fibroid is predominantly
on the outside of the uterus with projection into the pelvis and
abdomen then it may outgrow its own blood supply and degenerate
or become infected, resulting in pain and irritability (contractions)
of the uterus that can be associated with complications of pregnancy
(preterm labor, severe pain).
Most fibroids do not seem to interfere with fertility. Fibroids
should not be removed unless a reproductive problem is identified
and all other treatable causes for the problem have been evaluated
and either treated or excluded. One exception is the presence
of a large intrauterine filling defect seen on HSG, which should
be removed. Another exception is a fibroid compressing the fallopian
tubes or creating a tremendous distortion of the uterine cavity.
More information on the Hysterosalpingogram is available here.