According to Obstetrics and Gynecology Clinics of North America, approximately 5 to 10 percent of infertile women live with uterine fibroids. Women of childbearing age who have fibroids may be the most interested in options to preserve fertility.
Among doctors, it is generally accepted that fibroids occurring in certain areas of the uterus impact fertility more so than others. It is important to regularly monitor fibroids, especially if a patient has trouble becoming pregnant.
Transvaginal ultrasound is an effective method for monitoring existing fibroids and detecting new fibroids as they develop.
How Uterine Fibroids Can Affect Fertility
One way that fibroids can possibly impact fertility is by distorting the endometrial cavity. Depending on a fibroid's location and size, it may disrupt endometrial receptivity and normal hormonal balance. One study in Reproductive Sciences links uterine fibroids to altered gene expression, which, in turn, affects the ability of a fertilized egg to implant normally in the endometrium.
Fibroid location is a critical factor in determining potential causes of infertility in otherwise healthy women. Clinicians today use the International Federation of Gynecology and Obstetrics (FIGO) classification system to better categorize uterine fibroids and plan treatments that may best preserve fertility.
Using the FIGO System to Inform Fertility Treatments
The FIGO classification system was developed in response to inconsistency in nomenclature describing abnormal uterine bleeding and its potential causes. The system categorizes uterine fibroids according to which region of the uterus is affected:
- Types 0 – 2: Generally, these fibroids occur in the submucosal uterine layers. Type 2 fibroids cross the submucosal and intramural barrier, with 50 percent or more of the fibroid existing in the intramural layer.
- Types 3 – 5: These categories describe fibroids in the intramural space. Type 5 fibroids overlap both the intramural and subserosal layers of the uterus, with 50 percent or more of the growth in the intramural layer.
- Types 6 – 7: These uterine fibroids are those occurring in the subserosal layer. Generally, Type 7 fibroids are pedunculated from the uterus.
- Type 8: It's possible for fibroids to develop in ectopic locations, such as the cervix. Type 8 describes these types of fibroids.
While fibroids can occur in any uterine layer, not all of them relate to infertility: Submucosal fibroids significantly reduce the likelihood of pregnancy; intramural fibroids also reduce pregnancy rates, but not as significantly as submucosal fibroids.
Determining a fibroid's placement according to the FIGO classification system helps clinicians determine which fibroids may actually impact fertility in a specific patient. Additionally, this classification helps guide treatment decisions: if a fibroid is present in the submucosal layer, treatment - including surgery- may be necessary to preserve fertility. Conversely, if a fibroid is located in the subserosal layer, treatment for preserving fertility is usually unnecessary.
Using Ultrasound to Monitor Fibroids
Ultrasound offers clinicians a reliable and cost-effective method of diagnosing and classifying uterine fibroids. The benefit of 3D ultrasound is that it adds even more detail to a pelvic ultrasound exam by illuminating a third imaging plane: the coronal view. This added visibility allows a physician to attain a complete view of the gynecological anatomy, aiding the detection of intracavitary uterine abnormalities such as fibroids.
3D Ultrasound Image of Uterus with Fibroid
Some treatment options such as hysterectomy or myomectomy effectively manage fibroids. Depending on the size and location of the fibroid(s), the clinician may choose to use the transabdominal approach, transvaginal approach or both. Some treatment options such as myomectomy effectively manage fibroids, but may greatly impact a patient's fertility. Ultrasound-guided radiofrequency ablation is an alternative treatment that is also very effective and avoids complications such as damage to the endometrium and uterine blood vessels. This choice may be best for women with fibroids who still want to become pregnant.
Knowing how to classify uterine fibroids leads to better monitoring and treatment decisions. Ultrasound is a dependable way to monitor the growth and positioning of fibroids, which can help you determine which fibroids may improve the most with treatment and accurately predict their impact on a patient's fertility.