Uterine Factor Infertility: Symptoms, Types, Causes and Treatment

Uterine factor infertility (UFI) is a significant yet sometimes overlooked cause of female infertility. Affecting up to 1 in 500 reproductive-age women, UFI can arise from a wide spectrum of structural or functional problems with the uterus, ranging from congenital absence to acquired conditions like fibroids or adhesions. This comprehensive article explores the symptoms, types, causes, and evolving treatments for uterine factor infertility, synthesizing recent research and clinical findings to provide a clear, patient-focused overview.

Symptoms of Uterine Factor Infertility

Uterine factor infertility can manifest through a variety of symptoms, though some women may be asymptomatic until they attempt to conceive. Recognizing these signs is crucial for early diagnosis and intervention.

Symptom	Description	Impact on Fertility	Source(s)
Heavy Bleeding	Excessive menstrual flow	May indicate uterine niche, polyps, fibroids, or other abnormalities	1, 6
Intermenstrual Spotting	Bleeding between periods	Associated with uterine niche or endometrial changes	1
Pelvic Pain	Discomfort or pain in pelvic region	May suggest adhesions, endometriosis, or myomas	1, 9
Infertility	Inability to conceive after 12 months	Direct impact; central symptom of UFI	1, 3, 4
Recurrent Miscarriage	Multiple pregnancy losses	Seen with uterine malformations, adhesions, or fibroids	2, 9

Table 1: Key Symptoms of Uterine Factor Infertility

Understanding the Symptoms

Heavy Menstrual Bleeding and Spotting

• Women with uterine abnormalities such as scar defects (niches), fibroids, or polyps can experience heavier periods or irregular spotting.
• Reduced residual myometrial thickness (RMT) following cesarean section scars is significantly associated with both heavy bleeding and new infertility, especially when the RMT drops below 2.5 mm 1.

Pelvic Pain

• Persistent pain may point to intrauterine adhesions (synechiae), chronic endometritis, or endometriosis, all of which can compromise the uterine environment needed for implantation and pregnancy 1, 9.

Infertility and Recurrent Pregnancy Loss

• For many women, the first and only sign of UFI is difficulty in conceiving or repeated miscarriages.
• Uterine malformations (such as septate uterus), intrauterine adhesions, and submucous fibroids are linked to both infertility and recurrent pregnancy loss 2, 9.

When to Seek Help

• If you experience any of these symptoms—especially if they are persistent or worsening—consultation with a gynecologist or fertility specialist is recommended.
• Early detection and intervention can improve outcomes and expand treatment options.

Types of Uterine Factor Infertility

Uterine factor infertility is a complex diagnosis, encompassing several distinct subtypes based on structural and functional characteristics. Understanding these types helps guide individualized treatment approaches.

Type	Description	Example Conditions	Source(s)
Congenital	Present from birth, due to developmental issues	Uterine agenesis, septate uterus	3, 4, 13
Acquired	Develops later in life, often from disease or surgery	Myomas, adhesions, polyps, niche	3, 4, 5
Absolute UFI	Complete absence or non-functioning uterus	Mayer-Rokitansky-Küster-Hauser syndrome, post-hysterectomy	4, 13, 14
Non-Absolute UFI	Partial dysfunction, uterus present but impaired	Adenomyosis, cavity distortion	4, 13

Table 2: Major Types of Uterine Factor Infertility

Exploring the Types

Congenital Uterine Factor Infertility

• Uterine agenesis: Complete absence of the uterus, often seen in Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome 3, 13.
• Uterine malformations: Abnormal development such as septate, bicornuate, or unicornuate uterus can compromise fertility and increase miscarriage risk 2, 4.

Acquired Uterine Factor Infertility

• Myomas (Fibroids): Benign tumors that may distort the uterine cavity and hinder embryo implantation 2, 4, 5.
• Intrauterine Adhesions (Asherman Syndrome/Synechiae): Scar tissue formation after surgery or infection can obliterate or distort the uterine cavity 2, 4.
• Polyps: Localized overgrowths of endometrial tissue, often benign but capable of interfering with implantation 2, 6.
• Uterine Niche: Scar defects post-Cesarean section, associated with abnormal bleeding and infertility 1.

Absolute vs. Non-Absolute UFI

• Absolute UFI: No uterus present or uterus incapable of supporting pregnancy (e.g., after hysterectomy, congenital absence) 4, 13, 14.
• Non-Absolute UFI: Uterus present but not fully functional due to malformations, adenomyosis, or other disorders 4, 13.

Causes of Uterine Factor Infertility

The origins of UFI are diverse, ranging from birth defects to acquired diseases or injuries. Pinpointing the underlying cause is essential for effective management.

Cause	Example Conditions	Mechanism of Infertility	Source(s)
Congenital Anomalies	Agenesis, septate/bicornuate uterus	No uterus or abnormal cavity shape	3, 4, 13
Surgical Removal	Hysterectomy	Absence of uterine cavity	4, 13, 14
Fibroids/Myomas	Submucous, intramural fibroids	Distortion of cavity, poor implantation	2, 4, 5, 6
Adhesions/Synechiae	Asherman syndrome	Cavity obliteration, impaired receptivity	2, 4, 6
Polyps	Endometrial polyps	Obstruction, altered endometrial function	2, 6
Infection/Inflammation	Endometritis, chronic PID	Tissue damage, impaired implantation	7, 10, 11
Uterine Niche	Cesarean scar defects	Abnormal bleeding, embryo implantation issues	1
Adenomyosis	Endometrial tissue in myometrium	Poor receptivity, abnormal contractility	4
Irradiation	Cancer treatment	Uterine atrophy, endometrial damage	4
Poor Perfusion	Vascular disorders	Insufficient blood flow for implantation	7

Table 3: Main Causes of Uterine Factor Infertility

Detailing the Causes

Congenital Anomalies

• Uterine agenesis and malformations are present from birth, leading to either the absence of the uterus or a non-functional uterine cavity 3, 4, 13.
• Women with MRKH syndrome have no uterus, while those with septate or bicornuate uterus have high risks of miscarriage and preterm labor 2, 4.

Acquired Causes

• Surgical removal (hysterectomy), performed for cancer, fibroids, or severe bleeding, results in absolute infertility 4, 13, 14.
• Fibroids, especially those that distort the uterine cavity (submucous), are strongly associated with reduced fertility and pregnancy loss 2, 4, 5, 6.
• Intrauterine adhesions (Asherman syndrome) often follow surgical procedures (like D&C), infection, or trauma, leading to a scarred, unresponsive endometrium 2, 4, 6.
• Endometrial polyps may cause abnormal bleeding and interfere with implantation 2, 6.
• Uterine niche following Cesarean section is linked with abnormal bleeding and infertility if the remaining myometrial thickness is very low 1.
• Adenomyosis (endometrial tissue in muscle wall) and irradiation (from cancer treatment) can both result in a hostile or non-receptive endometrium 4.
• Chronic infection or inflammation (such as endometritis) disrupts the uterine environment and may also affect ovarian function 7, 10, 11.

Functional and Vascular Factors

• Poor uterine perfusion (blood flow) can prevent successful implantation and is being investigated as an underappreciated cause of UFI 7.

Treatment of Uterine Factor Infertility

The management of UFI is highly individualized, depending on the specific cause, extent of uterine dysfunction, and patient preferences. Advances in reproductive medicine have expanded the range of options available.

Treatment	Indications	Success/Outcome	Source(s)
Hysteroscopic Surgery	Polyps, adhesions, septum, fibroids	Pregnancy rates up to 87% after adhesiolysis, 47% after metroplasty, 78% after polypectomy	2, 12
Myomectomy	Submucous/intramural fibroids	~50% pregnancy rate if cavity distortion present	2, 12
Hormone Therapy	Poor perfusion, thin endometrium	May improve uterine receptivity	7
Uterus Transplantation	Absolute UFI (no uterus)	42% pregnancy rate in early studies; high complication risk	13, 14, 15, 16
Assisted Reproduction	Mild uterine impairment	IVF/ICSI may be attempted, lower success if severe UFI	5
Surrogacy	Absolute or severe non-absolute UFI	Alternative where legal/available	13, 14
Medical Management	Endometritis, mild adenomyosis	Treats infection/inflammation	9, 10

Table 4: Major Treatment Options for Uterine Factor Infertility

Overview of Treatment Strategies

Surgical Interventions

• Hysteroscopic adhesiolysis for intrauterine adhesions (Asherman syndrome) has resulted in restored fertility, with term pregnancy rates up to 87% 2.
• Metroplasty (hysteroscopic septum resection) significantly reduces miscarriage rates and improves pregnancy chances in women with septate uterus 2.
• Hysteroscopic polypectomy has shown higher pregnancy rates compared to untreated patients (78% vs. 42%) 2, 12.
• Myomectomy (removal of fibroids) helps especially when fibroids distort the uterine cavity, with pregnancy rates around 50% 2.

Medical and Minimally Invasive Treatments

• Hormonal therapy can optimize endometrial thickness or address poor uterine perfusion, though evidence is still emerging 7.
• Antibiotics or anti-inflammatory medications are important in treating infections or inflammation (endometritis, PID) 9, 10.

Innovative Options: Uterus Transplantation

• Uterus transplantation (UTx) offers hope to women with absolute uterine factor infertility (no uterus or non-functional uterus).
• Since 2014, successful deliveries have been reported following UTx, but the procedure is still experimental, with a 42% pregnancy rate and significant surgical risks, including the possibility of graft loss and preterm birth 13, 14, 15.
• UTx allows women to experience pregnancy, which is preferred over surrogacy or adoption by many patients 13, 16.

Assisted Reproduction and Surrogacy

• IVF/ICSI may be attempted in cases where the uterus is partially functional, though success rates are lower for severe UFI 5.
• Gestational surrogacy remains an established route in some countries for women with absolute or severe non-absolute UFI, but legal and ethical considerations vary widely 13, 14.

Prognosis and Considerations

• The success of treatment depends on the cause and severity of UFI, as well as patient age, other fertility factors, and access to advanced reproductive technologies.
• Multidisciplinary and patient-centered care is essential for optimal outcomes.

Conclusion

Uterine factor infertility is a challenging but increasingly manageable condition. Advances in diagnostic techniques, minimally invasive surgery, and even uterus transplantation are expanding the possibilities for affected women.

Key Takeaways:

• UFI may present with heavy bleeding, pain, or only through failure to conceive or recurrent miscarriage.
• It includes both congenital and acquired types; some women lack a uterus entirely, while others have various degrees of uterine dysfunction.
• Causes range from birth defects and surgery to fibroids, adhesions, infections, and poor blood flow.
• Treatments include hysteroscopic surgery, myomectomy, hormone therapy, and emerging options like uterus transplantation.
• Prognosis depends on the underlying cause, with some women experiencing restored fertility after treatment and others requiring advanced interventions or surrogacy.
• Ongoing research and individualized care continue to improve outcomes and hope for women with UFI.

By understanding the diverse manifestations, causes, and treatments of uterine factor infertility, patients and clinicians alike can better navigate the journey toward family-building and reproductive health.