Fibroids & Infertility

What Are Fibroids?

Fibroids, also known as uterine fibroids or leiomyomas, are non-cancerous growths that develop in the muscle wall of the uterus. While many women with fibroids have no symptoms and conceive naturally, some fibroids can interfere with fertility and increase the risk of pregnancy complications.

How Do Fibroids Affect Fertility?

Fibroids & infertility refers specifically to situations where fibroids contribute to difficulty falling pregnant, recurrent miscarriage, or implantation failure during fertility treatment.

Not all fibroids affect fertility. The impact depends on:

Location: Fibroids inside the uterine cavity (submucosal) are most likely to interfere with implantation.
Size: Larger fibroids (usually over 4–5 cm) may reduce pregnancy rates.
Number: Multiple fibroids may distort the uterus.
Effect on uterine shape: Distortion of the cavity can affect embryo implantation.

Many women with fibroids conceive without treatment. However, careful assessment is important when pregnancy is delayed.

How Do Fibroids Interfere With Pregnancy?

Fibroids may affect fertility in several ways:

Blocking Sperm Pathway: Large fibroids near the cervix may prevent sperm from reaching the fallopian tubes.
Distorting the Uterine Cavity: Submucosal fibroids can reduce implantation rates.
Interfering With Blood Flow: Reduced blood supply to the uterine lining may affect embryo development.
Blocking Fallopian Tubes: Fibroids near the tube openings may prevent fertilisation.
Increasing Miscarriage Risk: Certain fibroids are associated with early pregnancy loss.
Impacting IVF Success: Fibroids that distort the cavity can lower embryo implantation rates.

Importantly, fibroids located on the outer surface of the uterus (subserosal fibroids) usually do not affect fertility.

Risk Factors for Fibroid-Related Infertility

Fibroids are common, particularly in women aged 30 to 45. However, not all women with fibroids experience fertility problems.

You may be at higher risk if you:

Are over 35: Age-related decline in egg quality combined with fibroids may reduce fertility.
Have heavy or painful periods: This may indicate cavity-distorting fibroids.
Have recurrent miscarriage: Fibroids may contribute to implantation problems.
Have failed IVF cycles: Undiagnosed fibroids may play a role.
Have a family history of fibroids.
Are of African or Afro-Caribbean background: Fibroids are more common and may develop earlier.

Symptoms of Fibroids Affecting Fertility

Some women have no symptoms. Others may experience:

Heavy menstrual bleeding
Pelvic pressure or pain
Pain during intercourse
Frequent urination
Irregular bleeding
Difficulty falling pregnant
Recurrent pregnancy loss

If infertility is present without obvious symptoms, imaging tests are often needed to detect fibroids.

Diagnosis of Fibroids

Assessment usually includes:

Detailed Medical History: Menstrual pattern, pregnancy history, miscarriages.
Pelvic Examination: May detect an enlarged or irregular uterus.
Transvaginal Ultrasound: First-line imaging to assess size and location.
Saline Infusion Sonography: Helps visualise cavity distortion.
Hysteroscopy: Direct visualisation of the uterine cavity.
MRI Scan: Used when complex fibroids are suspected.
Fertility Testing: Ovulation tracking, hormone tests, semen analysis, and tubal assessment.

The goal is to determine whether fibroids are the likely cause of infertility or whether other factors are involved.

Types of Fibroids That Affect Fertility

Fibroids are classified based on location:

Submucosal Fibroids: Grow inside the uterine cavity. These have the greatest impact on fertility and miscarriage risk.
Intramural Fibroids: Grow within the uterine muscle. Large intramural fibroids that distort the cavity may affect implantation.
Subserosal Fibroids: Grow on the outer surface of the uterus. Usually do not affect fertility.
Cervical Fibroids: Rare but may interfere with sperm transport.

Submucosal fibroids are most strongly associated with reduced pregnancy rates.

Treatment Options for Fibroids & Infertility

Treatment depends on symptoms, size, location, age, and reproductive goals.

Conservative Monitoring

Small, asymptomatic fibroids: May simply be monitored.
No cavity distortion: Treatment may not be required before trying to conceive.

Medical Management

Hormonal medications can reduce bleeding but do not permanently eliminate fibroids. They are generally not used when actively trying to conceive.

Surgical Treatment (Myomectomy)

Surgical removal of fibroids is often recommended if fertility is affected.

Hysteroscopic Myomectomy: Used for submucosal fibroids. A camera is inserted through the cervix, and the fibroid is removed without abdominal incisions.
Laparoscopic Myomectomy: Minimally invasive surgery for intramural fibroids.
Open Myomectomy: May be required for multiple or very large fibroids.

Pregnancy is usually advised several months after surgery to allow healing.

Myomectomy can improve pregnancy rates in carefully selected patients, particularly when submucosal fibroids are removed.

How Do Fibroids Affect IVF Treatment?

Fibroids can reduce IVF success if they:

Distort the uterine cavity
Reduce endometrial receptivity
Increase inflammation
Cause repeated implantation failure

Removing cavity-distorting fibroids before IVF often improves outcomes.

However, not all fibroids need removal before IVF. Individual assessment is essential.

What Happens if Fibroids & Infertility Are Untreated?

If fibroids significantly distort the uterus and are left untreated:

Conception may be delayed
Miscarriage risk may increase
IVF success rates may be reduced
Pregnancy complications may occur, including preterm birth or abnormal fetal position

However, many women with fibroids conceive naturally and have healthy pregnancies. Treatment decisions must be individualised.

Can Fibroid-Related Infertility Be Prevented?

There is no guaranteed way to prevent fibroids. However, early assessment can reduce complications.

Regular gynaecological check-ups
Early fertility evaluation if pregnancy is delayed
Prompt imaging when symptoms develop
Managing heavy bleeding early

Healthy lifestyle choices such as maintaining a healthy weight and managing stress may support overall reproductive health, although they do not directly prevent fibroids.