A-Z of Uterine Fibroids: All You Need to Know

Uterine fibroids are a common gynecological condition that affects many women during their reproductive years. Also known as uterine myomas or leiomyomas, they represent benign muscular tumors within the uterine wall. 

In this in-depth guide, we will examine uterine fibroids, their underlying causes and risk factors, signs and symptoms, classification based on location, diagnostic methods, potential complications, and treatment approaches.

A thorough understanding of this condition can help women make informed decisions regarding their reproductive health.

What are Uterine Fibroids?

Uterine fibroids, also known as leiomyomas, refer to non-cancerous growths that develop within the muscular wall of the uterus, known medically as the myometrium. They range in size from just a few millimeters to several centimeters across and can be present as a single tumor or multiple growths. Despite being non-cancerous, uterine fibroids can cause significant symptoms depending on their number, location, and size.

Causes and Risk Factors

While the exact causes remain unclear, certain factors are known to increase a woman’s risk of developing uterine fibroids:

Genetics

Family history appears to increase risk, indicating a hereditary component. Studies of twins suggest genetic heritability ranging from 25-75%. Specific genes linked to fibroid formation control tissue growth and response to estrogen. Variations in these genes may predispose some women. 

Reproductive Hormones

Estrogen and progesterone are understood to promote fibroid growth by binding to receptor sites on the tumors. Higher lifetime estrogen exposure from factors like early menarche, late menopause, or no pregnancies is correlated with increased prevalence. This explains why fibroids often shrink after menopause due to declining hormone levels. 

Obesity and Metabolic Factors

Excess body weight raises estrogen levels via aromatase enzyme activity in fat tissue. Obese women have higher risks, with each 5-unit BMI increase correlating to 10% greater odds of fibroids. Conditions like diabetes that disrupt metabolism may also influence hormonal balance and cellular signaling pathways involved in tumor formation.

Racial Differences

African American women suffer disproportionately, with fibroids developing at earlier ages and growing more aggressively. Genetic variations prevalent in some ethnicities may interact with environmental exposures to exacerbate hormonal impacts on smooth muscle cell proliferation in the uterus.

Other Reproductive Traits

Parity seems protective—with each full-term pregnancy reducing risk by 10%. This may relate to hormonal changes during and after pregnancy suppressing tumor growth. By contrast, early menarche before age 12, late menopause, and lack of childbearing are all consistently implicated as risk enhancers.

Lifestyle Influences

Diet quality, exercise habits, alcohol use, and stress levels can indirectly impact fibroid development by altering hormone production and metabolism. More research is needed to clarify the relationships between lifestyle behaviors and uterine fibroid formation.

Classification Based on Location

Uterine fibroids are classified according to their position within the uterus. The three main classifications are:

Subserosal Fibroids

Subserosal fibroids grow outwardly on the outer uterine layer called the serosa. Because they are on the exterior of the uterus, they typically cause few issues other than an enlarged abdomen. In many cases, subserosal fibroids are best monitored without active treatment.

Intramural Fibroids

Intramural fibroids develop within the middle uterine muscular layer (myometrium), accounting for 70% of cases. Symptoms relate to their size and can include heavy bleeding or pain. Depending on the number and dimensions, intramural fibroids may be suitable candidates for myomectomy or embolization.

Submucosal Fibroids

Submucosal fibroids can distort the uterine cavity by occurring beneath the inner uterine lining (endometrium). This type often causes weighty periods due to their proximity. They also pose higher risks of infertility and miscarriage by interfering with embryo implantation and development. As such, submucosal fibroids frequently require surgical treatment.

Read Also: Understanding Urinary Tract Infections (UTIs)

Signs and Symptoms

Symptoms vary depending on fibroids’ size, number, and location within the uterus. Common symptoms of uterine fibroids include heavy menstrual bleeding, painful periods, and pressure-related bladder or bowel issues. Let’s explore these and other indications in more depth:

Heavy Menstrual Bleeding

Excessively heavy periods, lasting seven days or more, are a hallmark symptom in about 30% of fibroid cases. Submucosal tumors near the uterine lining can cause particularly heavy shedding of the endometrium each month.

Painful Periods (Dysmenorrhea)

Around 25% of women with fibroids experience painful cramps, which may be felt in the lower back, abdomen, or thighs. This could signal larger subserosal or intramural tumors applying pressure within the pelvis. 

Bleeding Between Periods

Intermenstrual spotting or bleeding may occur in 10-15% of cases, especially with submucosal fibroids near the endometrial cavity. 

Bladder Issues

Frequent urination or urgency due to direct bladder pressure is reported. Constipation may also result from bowel compression in the lower abdomen.

Abdominal/Pelvic Pressure

Fibroids can enlarge the uterus, causing a feeling of fullness, heaviness, or swelling in the lower abdomen. This may cause discomfort during activities like exercise.

Pain During Sex

Deep, painful sex is possible when large fibroids impinge on sensitive pelvic structures. Position changes may help alleviate pain. 

Diagnosis

For patients presenting with signs or a family history raising suspicion of fibroids, confirmatory testing is usually pursued. A pelvic exam allows external palpation of the uterus for irregularities. Transvaginal ultrasound then provides an excellent first-line internal visualization. 

On ultrasound, fibroids appear as distinct nodular masses of varying size, number, and location within the uterus. Features like echotexture, borders, and relationship to other pelvic organs are evaluated. Any suspicious areas can be further assessed.

For some patients, additional imaging may be helpful. Pelvic MRI provides superb soft tissue contrast for delineating fibroids. It can help when ultrasound views are limited by body habitus. Occasionally, a hysteroscopy is performed to inspect the endometrial cavity.

Lab tests are not usually diagnostic but can support the clinical picture. A complete blood count checking hemoglobin levels may indicate anemia from heavy bleeding.

Potential Complications

While uterine fibroids themselves are typically benign, their effects on reproductive and pelvic health can produce concerning issues if left unchecked. Let’s review some of the main complications that may arise:

Heavy Menstrual Bleeding: As mentioned, excessive bleeding is a hallmark symptom in about 30% of cases. Over time, recurrent iron deficiency anemia can result if bleeding is uncontrolled.

Infertility: Submucosal fibroids distorting the uterine cavity have been linked to impaired embryo implantation and higher miscarriage rates. Around 25% of infertile women have been found to have fibroids. 

Recurrent Pregnancy Loss: By interfering with placentation, submucosal tumors, in particular, increase the risks of miscarriage before 20 weeks gestation. Up to 30% of recurrent early losses involve undiagnosed fibroids.

Preterm Birth: Very large or numerous fibroids may cause the uterus to contract prematurely. They also pose higher risks of low birth weight, preeclampsia, and placental abnormalities in pregnancy. 

Obstructed Labor: During delivery, fibroids can block the birth canal. Depending on location, they increase cesarean delivery odds 1.5 to 3-fold compared to women without fibroids. 

Postpartum Hemorrhage: Degenerating fibroids may bleed excessively following a vaginal birth. The added risks of hemorrhage can endanger both mother and baby.

Treatment Options

Given the various presentations and impacts of uterine fibroids, treatment approaches are individualized based on factors like age, symptoms, future fertility desires, tumor characteristics, and medical history. Options include:

Medication

For some women, over-the-counter pain relievers or hormonal contraceptives suffice to manage minor bleeding or pain issues. Progestin-releasing devices (Mirena IUD) may help control heavy periods.

Uterine Fibroid Embolization (UFE)

A minimally invasive radiological procedure to cut off blood flow to fibroids. It can shrink tumors up to 80% but does not remove them. Fertility is usually preserved, and recovery is often quicker than surgery. However, potential risks include radiation exposure, allergic reactions to contrast, and rare complications. 

Myomectomy

Surgical removal of the fibroids alone while keeping the uterus. This is an option when desiring future fertility or to control severe symptoms. A laparoscopic approach enables faster recovery versus open abdominal surgery. Regrowth of non-removed fibroids is possible.

Hysterectomy

Removal of the entire uterus is recommended when childbearing is complete. It is the only way to cure fibroids definitively, but eliminates future pregnancy potential. Abdominal, vaginal, and robotic-assisted hysterectomy methods exist. 

Newer Options

Emerging techniques like magnetic resonance-guided focused ultrasound aim to destroy fibroids non-invasively using thermal energy. Research is still evaluating safety and effectiveness.

Conclusion

Uterine fibroids are a common gynecological issue that can significantly impact the quality of life. While the exact causes remain elusive, modifiable risk factors provide avenues for prevention. With this guide, you’ve learned the classification, diagnosis, potential issues, and various treatment approaches. See a Doctor immediately, if you are experiencing two or more of the symptoms listed above.