Uterine Anomalies In Infertility
By Dr M Faesen
Congenital Uterine Anomalies
WHAT ARE CONGENITAL UTERINE ANOMALIES?
These occur when the two contributing Muellerian tubes coming from the right and left-hand side do not fuse nicely in the midline, and therefore the uterus and often also the top of the vagina are not formed properly. They are therefore also called Muellerian duct anomalies.
Occurrence is less than 10% in the general population, perhaps a bit higher in the women who struggle to fall pregnant (subfertility).
Most frequent anomalies are, in order of frequency:
- Arcuate uterus:
- Septate uterus
- Bicornuate uterus
Other congenital anomalies such as unicornuate uterus, uterus didelphys are far less common.
Of the 3 most common anomalies, the bicornuate uterus usually does not require surgery.The arcuate uterus only needs surgery if there is repeated implantation failure, or recurrent pregnancy loss.
There is general consensus that a uterine septum needs to be removed. This usually can be done with the hysteroscope, and preferably with scissors rather than electrical loop or hook.
WHAT ARE THE MOST COMMON UTERINE ANOMALIES?
Acquired uterine anomalies:
WHAT IS A FIBROID?
Fibroids, also called myomas (or more scientific leiomyomas), are benign growths inside the uterus. They originate from the muscular part of the uterus, and are formed of balls of muscle fibres.
They can grow inside the uterine wall (intra-mural), just on the surface of the uterus (sub-serosal), or deep inside the uterus, almost or completely into the endometrial cavity (submucous).
WHAT TREATMENTS ARE AVAILABLE FOR FIBROIDS?
In terms of treatment there are some general guidelines.
Any fibroid that causes symptoms in terms of heavy or painful menstruation, will need to be removed or disabled (see embolization below). If the fibroid is not causing symptoms, it can be observed and probably does not require any intervention until such time that it does cause problems.
In a subfertile patient however, fibroids will need to be surgically removed if:
- The fibroids distort the endometrial cavity:
- Submucous (category 0, 1, 2),
- Intramural (category 3, 4, 5),
- The fibroid inside the wall of the uterus is close (< 5mm) to the endometrium
- The fibroid inside the wall of the uterus is 5 cm or larger.
The fibroids on top of the surface of the uterus (subserosal) or on a stalk (pedunculated) on top of the uterus, seldom cause problems, and therefore only rarely need to be removed, except if very large (for example a football size fibroid can cause pressure symptoms).
ARE THERE ALTERNATIVE TREATMENTS FOR FIBROIDS?
Alternative treatment for fibroids:
GnRH analogues such as Lucrin or Zoladex will temporarily stop the growth of the fibroids, but the effect disappears when the medication is stopped.
Medication therefore is only used in preparation for surgery to try and make the fibroid a bit smaller and hopefully easier to remove.
The medication has serious side effects and is very expensive, and therefore the medication can only be used for a maximum of 6 months. When the effect of the medication wears off, the fibroids usually start growing again, making this treatment not favourable for long term treatment.
Uterine Artery Embolization
With angiography the feeding blood vessels to the fibroids can selectively be blocked. This is done by an interventional radiologist, not a gynaecologist. The procedure will stop the blood supply to the fibroid, and will then prevent further growth of that fibroid. It is important to note that this treatment will not remove the fibroid.
After embolization with time, the fibroid will shrink, will reduce in size, but it will stay in its position. Symptom relief is usually achieved in the majority of cases. It will not help the subfertile patient since the fibroid is not removed.
WHAT IS A UTERINE POLYP?
These are usually small or very small and soft benign growths inside the cavity of the uterus and originate from the endometrium that lines the uterine cavity. When small (less than 5 mm) they are often very difficult to see on an ultrasound.
If they are small (less than 5 mm) they usually do not cause any symptoms and are often only discovered by chance during hysteroscopy for other reasons (subfertility workup).
Larger polyps (1 cm or more) usually are visible on ultrasound. With the help of a small amount of saline infusion into the uterus, the fluid can then outline the polyp and confirm the diagnosis.
In the subfertile patient, there is no consensus about the effect of small uterine polyps. If the polyps are very small (less than 5 mm), removal is usually not required.
However, since the majority of very small polyps is only discovered during hysteroscopy done for other reasons, the surgeon doing the hysteroscopy will usually remove them anyway.
Only if the polyps are large (more than 1 cm), the consensus is that they will need to be removed, especially in the subfertile patient. This can usually be done with the hysteroscope in a day procedure.
WHAT IS AN ADHESION?
Intra-uterine adhesions are bands of scar tissue, usually caused by previous procedures done on the inside of the uterus. Common reasons for scar tissue are:
- Vigorous curettage (womb scrape), either a diagnostic curettage or curettage for retained products of conception after a miscarriage
- Removal of submucous fibroids, especially if there are fibroids on opposite walls
- Chronic serious infections, as for example tuberculosis of the uterus
Intra-uterine adhesions can sometimes be very difficult to deal with. The ideal procedure is hysteroscopy and division of all visible scar tissue that distorts the uterine cavity.
However, sometimes the adhesions are extremely dense, and consequently it is very difficult to recognize the normal uterine cavity. This might require removal in several stages, or it may not be possible at all if the uterine cavity is completely destroyed.
Even after scar removal, there is often a need to repeat the hysteroscopy a few weeks later, because some of the scar tissue may come back and jeopardize the results of fertility treatment.
Other uterine anomalies in subfertility:
WHAT IS ADENOMYOSIS?
Endometrial glands sometimes breach the border between the endometrium (the lining) and the myometrium (muscle layer) of the uterus. They grow into the muscle layer of the uterus. It occurs in about 20-30% of women in reproductive age groups. Sometimes adenomyosis does not cause any symptoms, but most of the time the patient complain about severe period pains, or even painful intercourse, and can cause abnormal bleeding patterns.
Diagnosis can often be made on routine ultrasound also using Doppler, but the best modality is an MRI scan.
Adenomyosis can cause subfertility when it is extensive, and it reduces the chances of implantation of the embryos and increases the miscarriage rates.
If the adenomyosis is localised, it can usually be surgically removed. Sometimes the adenomyosis is diffuse through a larger section of the muscle layer, and then surgical removal would do too much damage to the uterus. Surgery then would best be avoided.
If diffuse throughout the muscle layer of the uterus, only suppression with GnRH analogues would possibly help, followed by the required fertility treatment.
Sometimes adenomyosis can be seen as pigmented spots bulging through the endometrium, as seen during hysteroscopy. It is especially this type of adenomyosis very close or in the endometrium that causes chronic inflammation and reduces implantation. These can then easily be opened and drained with small scissors.
Get in touch to find out more about your uterine health today.