What Are Uterine Fibroids and How Do They Affect Fertility?
Uterine fibroids are benign (non-cancerous) growths that develop in or on the uterus. These muscular tumors are common in people assigned female at birth and often arise during reproductive years. The impact of uterine fibroids on fertility varies widely, depending on their size, number, and location within the uterus. Fibroids can interfere with conception and pregnancy in some cases but are not always the cause of infertility. Understanding the relationship between uterine fibroids and fertility is a crucial step for individuals or couples trying to conceive, whether naturally or through assisted reproductive technology such as IVF.
Key Takeaways
- Uterine fibroids are non-cancerous growths in or on the uterus, which may affect fertility in some individuals.
- The size, number, and location of fibroids play a critical role in whether they impact conception or pregnancy.
- Submucosal and intramural fibroids are most associated with negative effects on fertility, especially when they distort the uterine cavity.
- Fibroid-related infertility is not inevitable: many people with fibroids can conceive and carry healthy pregnancies.
- Removal of fibroids (myomectomy) can improve fertility outcomes in certain cases, particularly for symptomatic or cavity-distorting fibroids.
- Minimally invasive procedures like uterine artery embolization are generally not first-line for those seeking future fertility due to potential risks.
- Fibroids may increase the risk of miscarriage and certain pregnancy complications, but most individuals with fibroids have healthy pregnancies.
- Consulting a fertility specialist is recommended if you have fibroids and difficulty conceiving, recurrent miscarriage, or are considering IVF.
- Lifestyle factors and genetics can influence fibroid growth and their impact on reproductive health.
- Comprehensive evaluation and individualized treatment planning are vital for optimizing fertility in the presence of uterine fibroids.
Table of Contents
- What Are Uterine Fibroids?
- How Do Uterine Fibroids Affect Fertility?
- Types and Locations: Intramural, Submucosal, and Subserosal Fibroids
- Symptoms of Uterine Fibroids Relevant to Fertility
- How Are Uterine Fibroids Diagnosed?
- Uterine Fibroids and Natural Conception
- Fibroids and IVF: Implications for Assisted Reproductive Technology
- Uterine Fibroids and Pregnancy Outcomes
- Miscarriage Risk and Fibroids
- Treatment Options: Myomectomy, Fibroid Embolization, and More
- Quick Facts Table: Uterine Fibroids and Fertility
- Myths vs. Facts About Uterine Fibroids and Fertility
- When to See a Fertility Specialist About Fibroids
- Frequently Asked Questions About Uterine Fibroids and Fertility
- References and Further Reading
- Disclaimer
What Are Uterine Fibroids?
Uterine fibroids, also known as leiomyomas or myomas, are benign tumors that develop from the muscular tissue of the uterus. They differ in size from small, undetectable nodules to large masses that can enlarge and distort the uterus. Fibroids are extremely common; by age 50, up to 70-80% of people with uteruses will have developed at least one fibroid, although not all will have symptoms or fertility issues (Bulun, 2013).
Fibroids are classified by their location:
- Intramural fibroids: Develop within the muscular wall of the uterus.
- Submucosal fibroids: Grow just beneath the endometrial lining and protrude into the uterine cavity.
- Subserosal fibroids: Extend outward from the outer uterine surface.
Did you know? Most fibroids are asymptomatic and many people never know they have them unless discovered during a routine pelvic exam or imaging for another reason.
How Do Uterine Fibroids Affect Fertility?
Uterine fibroids may impact fertility in several ways, but not every fibroid causes problems with conception or pregnancy. The effects depend largely on their size, type, and especially their location in relation to the uterine cavity.
- Submucosal fibroids are the most closely associated with infertility, as they can distort the uterine cavity, interfere with implantation, and increase miscarriage risk (Pritts, 2009).
- Intramural fibroids may reduce pregnancy rates, particularly if they are large (>4 cm) or distort the uterine cavity.
- Subserosal fibroids tend not to impact fertility unless very large or numerous.
The mechanisms by which fibroids impact fertility include:
- Hindering sperm transport.
- Disrupting embryo implantation.
- Altering uterine contractions.
- Causing changes in uterine blood flow.
Key Point: The majority of people with fibroids conceive without difficulty; targeted evaluation is needed only if infertility or recurrent pregnancy loss occurs.
Types and Locations: Intramural, Submucosal, and Subserosal Fibroids
Intramural Fibroids and Fertility
Intramural fibroids are embedded within the uterine wall. Large or multiple intramural fibroids can sometimes disrupt the uterine cavity, potentially affecting embryo implantation and pregnancy maintenance. Several studies suggest that removal of cavity-distorting intramural fibroids can improve fertility; however, those not distorting the cavity may have minimal effect (Pritts, 2009).
Submucosal Fibroids and Fertility
Submucosal fibroids protrude into the uterine cavity and are most strongly linked with infertility and recurrent miscarriage. These fibroids can physically block the embryo from implanting and alter the endometrial environment. Even small submucosal fibroids can reduce fertility rates (Metwally, 2012).
Subserosal Fibroids
Subserosal fibroids develop on the outside of the uterus and typically do not influence fertility directly, unless they grow large enough to compress the fallopian tubes or neighboring organs (Murji, 2020).
Scenario Example: Anna is a 36-year-old with a 7 cm intramural fibroid that slightly distorts her uterine cavity. After experiencing two early miscarriages, her fertility team recommends myomectomy, which increases her chance of a successful pregnancy.
Symptoms of Uterine Fibroids Relevant to Fertility
While many fibroids are silent, symptomatic fibroids can produce signs and symptoms including:
- Heavy or prolonged menstrual bleeding.
- Pelvic pain or pressure.
- Frequent urination.
- Pain during intercourse.
- Lower back pain.
For fertility, the most concerning symptoms are heavy menstrual bleeding (which may lead to anemia) and recurrent pregnancy loss.
Did you know? Many fibroids do not cause pain but still affect fertility by distorting the uterine cavity or altering the endometrial lining.
How Are Uterine Fibroids Diagnosed?
Most fibroids are discovered through pelvic imaging or during evaluation for infertility or recurrent pregnancy loss. Common diagnostic tools include:
- Transvaginal ultrasound: First-line imaging for assessing fibroids.
- Saline infusion sonohysterogram: Helps identify submucosal fibroids.
- MRI: Used for complex cases or surgical planning.
- Hysteroscopy: Allows direct visualization of the uterine cavity.
Key Point: Accurate mapping of fibroid size and location is essential to guide treatment recommendations for fertility.
Uterine Fibroids and Natural Conception
While the majority of people with fibroids conceive naturally, certain fibroids can interfere with conception, especially those distorting the uterine cavity. The risk is influenced by:
- Fibroid size: Larger than 4 cm is more likely to impact fertility.
- Number of fibroids: Multiple fibroids increase the degree of uterine distortion.
- Location: Submucosal and large intramural fibroids are of greatest concern.
In general:
- Subserosal fibroids rarely affect natural conception.
- Intramural and submucosal fibroids are associated with lower conception rates if they distort the endometrial cavity (Pritts, 2009).
Fibroids and IVF: Implications for Assisted Reproductive Technology
Fibroids can affect the outcomes of in vitro fertilization (IVF) in various ways:
- Submucosal fibroids: Associated with reduced implantation and pregnancy rates in IVF cycles (Metwally, 2012).
- Intramural fibroids: May reduce IVF success, particularly if they distort the uterine cavity.
- Subserosal fibroids: Usually do not affect IVF outcomes.
Studies show that surgical removal of submucosal fibroids improves IVF pregnancy rates. The impact of intramural fibroids is more controversial, and decisions about removal should be guided by the presence of cavity distortion, symptoms, and fertility history.
Scenario Example: Damon and Taylor are pursuing IVF. Taylor has two submucosal fibroids. Their fertility team recommends hysteroscopic resection before starting IVF to optimize their chances.
Uterine Fibroids and Pregnancy Outcomes
Fibroids can influence several aspects of pregnancy and birth:
- Higher risk of miscarriage: Especially with submucosal or large intramural fibroids.
- Increased risk of preterm birth.
- Placental problems: Such as abruption or malpresentation.
- Cesarean delivery: More likely in the presence of large or multiple fibroids.
- Postpartum hemorrhage: Slightly increased risk.
However, it is important to note that many people with fibroids carry successful pregnancies and deliver healthy babies (Klatsky, 2008).
Miscarriage Risk and Fibroids
The risk of miscarriage is higher in people with fibroids, particularly with:
- Submucosal fibroids.
- Large intramural fibroids.
- Multiple fibroids.
A meta-analysis showed that people with fibroids had a miscarriage rate of about 14% compared to 7% in those without fibroids (Hartmann, 2017). Surgical removal of cavity-distorting fibroids can reduce miscarriage risk.
Key Point: Not all people with fibroids experience pregnancy loss; individualized assessment and treatment are crucial.
Treatment Options: Myomectomy, Fibroid Embolization, and More
When treatment is considered to improve fertility or reduce miscarriage risk, options include:
Myomectomy
- Definition: Surgical removal of fibroids, preserving the uterus.
- Indications: Symptomatic fibroids, submucosal/intramural fibroids distorting the cavity, previous failed IVF or recurrent pregnancy loss.
- Outcome: Improves fertility outcomes, especially with cavity-distorting submucosal fibroids (Pritts, 2009).
Uterine Artery Embolization (UAE)
- Definition: Minimally invasive procedure blocking blood supply to fibroids, causing them to shrink.
- Fertility impact: Not generally recommended for those wishing to conceive due to risk of impaired ovarian function and uterine scarring; reserved for select cases (Karlsen, 2018).
Medications
- GnRH agonists: Can shrink fibroids temporarily but not a long-term fertility solution.
- Other options: Oral therapies are generally for symptom control rather than fertility.
Emerging and Alternative Treatments
- MRI-guided focused ultrasound and other minimally invasive treatments are still being evaluated for fertility safety and effectiveness.
Quick Facts Table: Uterine Fibroids and Fertility
| Aspect | Key Details |
|---|---|
| Definition | Benign uterine tumors, also called leiomyomas |
| Prevalence | Up to 70-80% of people with uteruses by age 50 |
| Impact on Fertility | Depends on size, number, location (greatest with submucosal or cavity-distorting) |
| Common Symptoms | Heavy bleeding, pelvic pain, pressure, possible infertility, recurrent miscarriages |
| Key Diagnostic Tools | Ultrasound, MRI, hysteroscopy |
| Treatment Options | Myomectomy, medications, embolization, observation |
| Most Concerning Types | Submucosal, large intramural fibroids |
| Effect on IVF Outcomes | Reduced pregnancy/implantation rates with certain fibroids |
| Fertility Preservation | Myomectomy typically safest; embolization less favored for future fertility |
| When to Seek Specialist Care | Infertility, recurrent loss, large/symptomatic fibroids, before IVF |
Myths vs. Facts About Uterine Fibroids and Fertility
| Myth | Fact |
|---|---|
| All fibroids cause infertility | Most fibroids do not impact fertility unless they distort the uterine cavity |
| Uterine artery embolization is always safe for aspiring parents | This procedure can affect fertility and is not recommended for all |
| Removal of all fibroids is necessary for pregnancy | Only certain fertility-impacting fibroids need removal |
| Fibroids always lead to miscarriage | Most people with fibroids carry pregnancies to term |
| You cannot get pregnant if you have fibroids | Many people with fibroids conceive and deliver healthy babies |
When to See a Fertility Specialist About Fibroids
Consider consulting a reproductive endocrinologist (REI) or fertility specialist if:
- You have been trying to conceive for 12+ months (6+ months if over 35).
- You have a history of recurrent miscarriage.
- You have been diagnosed with submucosal or large intramural fibroids.
- You are considering fertility treatments such as IVF.
- You have symptoms like heavy bleeding, pelvic pain, or anemia.
A fertility specialist can individualize testing and treatment options to optimize your chances based on your unique situation.
Frequently Asked Questions About Uterine Fibroids and Fertility
What does "uterine fibroids fertility" mean?
“Uterine fibroids fertility” describes the relationship between the presence of uterine fibroids and an individual's ability to conceive and maintain a pregnancy. This term is often used in fertility discussions to evaluate whether fibroids may be interfering with reproductive outcomes.
Fibroids can sometimes cause infertility by blocking implantation or causing miscarriage; however, not all fibroids have this effect. The impact depends greatly on the type, size, and location of the fibroids, emphasizing the need for individualized assessment.
Can fibroids affect my ability to conceive naturally?
Yes, fibroids can affect natural conception, especially if they distort the uterine cavity. Submucosal and large intramural fibroids are most likely to cause issues.
Many people with fibroids conceive naturally, but those with multiple or particularly located fibroids may face challenges. Removal of certain fibroids can improve chances, so evaluation is important if you have concerns.
What types of fibroids interfere most with fertility?
Submucosal fibroids, which protrude into the uterine cavity, have the greatest impact on fertility. Large or cavity-distorting intramural fibroids are also concerning.
Subserosal fibroids are less likely to interfere with conception unless very large. Accurate imaging helps determine which fibroids, if any, need intervention for fertility.
Are fibroids linked to higher miscarriage rates?
Yes, people with fibroids, particularly submucosal or large intramural types, have higher miscarriage rates than those without fibroids.
Data suggests the risk of miscarriage in people with fibroids is about double that of those without. Removal of certain fibroids can help reduce this risk in many cases.
Can fibroids affect IVF success rates?
Certain fibroids, especially submucosal and cavity-distorting intramural fibroids, are linked to reduced IVF implantation and pregnancy rates.
Removal of these fibroids before IVF is associated with improved outcomes. Subserosal fibroids generally have minimal effect on IVF success.
Is removal of fibroids (myomectomy) always necessary to improve fertility?
No, not all fibroids need to be removed to improve fertility. Myomectomy is generally reserved for submucosal or cavity-distorting fibroids, or when symptoms are severe.
For small, asymptomatic fibroids that do not distort the uterine cavity, surgery is often not needed. A fertility specialist can help guide the decision.
What is the difference between intramural, submucosal, and subserosal fibroids?
- Intramural: Within the uterine wall; may impact fertility if large or cavity-distorting.
- Submucosal: Protrude into the uterine cavity; most strongly associated with infertility and miscarriage.
- Subserosal: On the uterine surface; rarely impact fertility.
Knowing the subtype is key for fertility planning.
How is the effect of fibroids on fertility diagnosed?
A combination of imaging (ultrasound, sonohysterography, MRI) and, sometimes, hysteroscopy is used to evaluate fibroids. The goal is to determine if fibroids distort the uterine cavity or block fallopian tubes.
A careful history and physical exam are also essential to assess symptoms and risks.
Can lifestyle or medications shrink fibroids and improve fertility?
Certain medications (like GnRH agonists) can temporarily shrink fibroids, but this is not a long-term fertility solution.
Lifestyle changes (maintaining a healthy BMI, avoiding smoking) may slow fibroid growth, but have limited direct impact on fertility outcomes for most people.
What is fibroid embolization, and is it safe for people wishing to conceive?
Uterine artery embolization is a minimally invasive procedure to shrink fibroids, but it is generally not recommended for individuals planning future pregnancies due to risks of reduced uterine function.
It is best reserved for those who have completed childbearing or who do not want surgery.
Does fibroid removal improve miscarriage rates?
Removal of submucosal or cavity-distorting fibroids (usually via myomectomy) can reduce miscarriage rates and improve the odds of maintaining a healthy pregnancy.
A fertility specialist can determine if surgery is appropriate based on size, location, and reproductive history.
Do all people with fibroids need to see a fertility specialist?
Not everyone with fibroids requires fertility evaluation. However, if you experience infertility, recurrent miscarriage, or are planning ART like IVF, consultation is wise.
Routine gynecologic care is usually sufficient if you have fibroids but no fertility concerns.
After myomectomy, how long should I wait before trying to conceive?
Most clinicians recommend waiting three to six months after myomectomy before attempting conception to allow the uterus to heal.
Your medical team will provide individualized guidance based on surgical type, fibroid characteristics, and your health.
Are certain people at increased risk for fibroids?
Yes, higher risk is associated with:
- Family history.
- Black ethnicity.
- Older reproductive age.
- Certain lifestyle factors (obesity, high red meat intake).
Discuss risk factors with your provider if you have concerns.
Will every fibroid seen on ultrasound reduce my chances of pregnancy?
No, not every fibroid affects fertility. Small, subserosal, or non-cavity-distorting fibroids are unlikely to impact conception or pregnancy.
Individual assessment is necessary to determine which, if any, fibroids may be concerning.
Can fibroids return after removal?
Yes, fibroids can grow back after removal, especially in younger people or those with multiple or large fibroids.
Regular gynecologic follow-up and monitoring can help detect recurrence.
What questions should I ask my doctor about fibroids and fertility?
Consider asking:
- Which type and location of fibroid(s) do I have?
- Do my fibroids affect the uterine cavity?
- Will removal improve my chance of pregnancy?
- Are there other causes of infertility to consider?
- What are my options if fibroids recur?
References and Further Reading
- Bulun SE. Uterine fibroids. N Engl J Med. 2013
- Pritts EA, Parker WH, Olive DL. Fibroids and infertility: an updated systematic review. Fertil Steril. 2009
- Metwally M, Cheong YC, Horne AW. Surgical treatment of fibroids for subfertility. Cochrane Database Syst Rev. 2012
- Hartmann KE et al. Uterine Fibroids. Agency for Healthcare Research and Quality. 2017
- Klatsky PC, Tran ND, Caughey AB, Fujimoto VY. Fibroids and reproductive outcomes: a systematic literature review. Hum Reprod Update. 2008
- Murji A, et al. Uterine fibroids, infertility, and reproductive outcomes: a review. Curr Opin Obstet Gynecol. 2020
- Karlsen K, et al. Uterine artery embolisation of symptomatic fibroids: impact on fertility and predictors of pregnancy. BJOG. 2018
- American Society for Reproductive Medicine (ASRM). Fibroids and reproductive health. ASRM - Fibroids
- European Society of Human Reproduction (ESHRE). Management of women with fibroids and infertility. ESHRE - Guidance
Disclaimer
This article is for informational and educational purposes only and does not constitute medical or mental health advice. It is not a substitute for speaking with a qualified healthcare provider, licensed therapist, or other professional who can consider your individual situation.
