Fibroids, which may affect fertility, are the most commonly
seen tumors of the female reproductive system.
What are fibroids?
Fibroids are the most common benign tumors in women of
reproductive age. These non-cancerous smooth muscle cell tumors are found in
30% of women but only 1 in 4 women display symptoms.
Fibroids are hormonally responsive, growing in the presence
of the female hormone estrogen. They are rarely found in girls who haven’t
started puberty and tend to disappear after menopause.
Types of fibroids and their impact on fertility
While many women with fibroids do not face fertility issues
and have successful pregnancies, certain fibroids are often found in women who
do face fertility issues.
The location of fibroid usually determines its impact on
fertility. In particular, submucosal fibroids, a form of uterine fibroids, are
known to negatively affect fertility.
Submucosal fibroids – Fibroids that grow right
beneath the uterus lining and may protrude into the uterine cavity. They affect
rates of implantation, pregnancy, miscarriage and live birth.
Subserosal fibroids – Fibroids that grow on the
outside of the uterus. They do not affect fertility.
Intramural fibroids – Fibroids that are found within
the wall of the uterus. Their impact on fertility remains uncertain. However,
recent studies have shown that they appear to impact rates of implantation and
clinical pregnancy, though less significantly than submucosal fibroids.
Studies have shown that the removal of intramural or
subserosal fibroids did not significantly improve the rates of conception and
pregnancy, unlike the removal of submucosal fibroids.
There are many explanations for how fibroids cause
infertility in women. Fibroids cause inflammation of the uterine lining and
change the local hormonal environment, affecting the implantation of the
embryo. Furthermore, large fibroids may interfere with sperm and egg interaction
or embryo migration by altering uterus contraction.
Evaluating fibroids
It is important to evaluate fibroids to determine its type
and the degree to which it may cause infertility.
Fibroids can be identified and distinguished by various
methods.
Ultrasound: An ultrasound effectively identifies
fibroids of up to 4 – 5 mm in diameter. However, ultrasound may not be the best
option for patients with multiple fibroids. Multiple fibroids cause acoustic
shadows, obstructing the travel of ultrasonic waves, resulting in a poor
detection of fibroids on ultrasound scans.
Hysterosalpingography: An x-ray of the uterus and
fallopian tubes can be performed to identify uterine fibroids.
Hysterosalpingography is often done to assess the openness of the fallopian tubes.
It is, however, not an ideal method to identify submucosal fibroids.
Hysterosonography: A hysterosonography, where a
sterile fluid is injected into the uterine cavity, is ideal for identifying
submucosal fibroids. The only downsides are the discomfort and risk of
infection (1%).
Magnetic Resonance Imaging (MRI): Despite the high
cost of an MRI, it is most reliable in identifying the location of fibroids.
Treating fibroids
For women who do not display symptoms, a cautious
watch-and-wait approach without treatment would suffice. Patients who decide to
treat the uterine fibroids for a variety of reasons – such as for fertility
enhancement or relief of symptoms – can decide between medication, surgery or
non-surgical procedures.
Medication
Women with fibroids can rely on medication to control their
symptoms, such as reduce menstrual blood loss. Other medical options are
primarily hormonal agents, as estrogens promote fibroid growth whereas progesterone’s
curb it, but are unsuitable for fertility. Due to the side effects of certain
medications, such as bone loss, they should only be used for a maximum of 6
months.
Surgery
Hysteroscopic myomectomy is the advisable surgical procedure
for the removal of fibroids. It is suitable for submucosal fibroids smaller than
5cm that are located within or bulging into the uterine cavity. Fibroids larger
than 5cm may require repeat procedures. Prior to surgical removal,
classification systems will be employed to accurately describe the submucosal
fibroids and assess the chances of successful hysteroscopic removal.
Laparoscopy (keyhole surgery performed through a very small
incision) and laparotomy (open surgery performed through a large incision) are
alternative options to surgically remove uterine fibroids. A keyhole surgery
may be more advantageous as it involves less postoperative pain, a quicker
recovery and less incidence of fever. However, a keyhole surgery is less common
due to its technical difficulty.
As surgical treatment of fibroids has its risks, such as
infection, patients should always weigh the decision for surgery against
potential risks.
Non-surgical treatment
Uterine artery embolization (UAE) and more recently,
MRI-Guided focused ultrasonography (MRgFUS) are new treatment methods.
In a UAE procedure, small particles are delivered to block
blood supply to the uterine body. An MRgFUS procedure uses high-frequency
ultrasound waves to kill cells and shrink fibroids. This is performed with the
help of MRI to guide the ultrasound beams to accurately target the fibroids.
However, as these techniques are not extensively used, there
is insufficient data on reproductive outcomes of patients who were trying to
conceive. As such, we do not yet recommend these procedures. Furthermore, there
is concern over the development of pelvic adhesions (scar tissues that stick
together) that obstruct the fallopian tubes, which may affect ovarian reserves
and fertility.
For more information or to make an appointment, please call 400-819-6622.
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