Blighted Ovum: Symptoms, Types, Causes and Treatment

A blighted ovum, also known as an anembryonic pregnancy, is a common cause of early pregnancy loss. For many, the diagnosis can be confusing and emotional, especially since early symptoms can mimic those of a healthy pregnancy. This article offers a comprehensive and evidence-based overview of blighted ovum, including its symptoms, types, causes, and available treatments, to provide clarity and support for anyone navigating this experience.

Symptoms of Blighted Ovum

When a woman experiences a blighted ovum, the initial symptoms often resemble those of a typical pregnancy. However, as time progresses, subtle and overt signs may indicate that something is amiss. Recognizing these symptoms early can help facilitate timely diagnosis and intervention.

Symptom	Early/Advanced	Typical Presentation	Source(s)
Vaginal bleeding	Advanced	Light to heavy spotting or bleeding	4
Abdominal pain	Advanced	Cramping or discomfort	4
Pregnancy symptoms loss	Advanced	Sudden decrease in nausea, breast tenderness, etc.	2
Low β-HCG levels	Early	Lower than expected for gestational age	2

Table 1: Key Symptoms

Understanding the Symptoms

Early Pregnancy Symptoms

Initially, a blighted ovum produces the same hormonal signals as a healthy pregnancy. Many women may experience:

• Missed periods
• Breast tenderness
• Nausea or morning sickness

These symptoms are due to the body’s response to rising pregnancy hormones, even though an embryo never develops.

Loss of Pregnancy Symptoms

As the pregnancy fails to progress, hormone levels like β-HCG begin to plateau or fall. This can lead to a sudden loss of early pregnancy symptoms:

• Nausea subsides abruptly
• Breasts feel less tender or swollen
• Fatigue lessens

Vaginal Bleeding and Abdominal Pain

Over time, the body may begin to expel the non-viable pregnancy tissue. This process is often accompanied by:

• Light spotting or heavier bleeding
• Mild to moderate abdominal cramps or pain
• In some cases, the tissue may pass without significant pain

A randomized controlled trial found that abdominal pain and bleeding are common during the medical management of blighted ovum, especially when medications like misoprostol are used to facilitate expulsion 4.

Laboratory Findings

A distinguishing feature in many cases is low β-HCG levels compared to what would be expected for the gestational age. This finding, particularly when combined with ultrasound showing an empty gestational sac, is a strong indicator of blighted ovum 2.

Types of Blighted Ovum

Blighted ovum presents in distinct forms, largely categorized based on timing and diagnostic features. Understanding these types helps clinicians and patients anticipate the clinical course and management options.

Type	Key Feature	Clinical Implication	Source(s)
Early diagnosis	Empty gestational sac before 8 weeks	Typically detected via early ultrasound	2 4
Late diagnosis	Gestational sac with yolk sac, but no embryo	Detected in later first trimester scans	2

Table 2: Types of Blighted Ovum

Differentiating the Types

Early-Diagnosed Blighted Ovum

• Detected when an ultrasound shows a gestational sac without an embryo or yolk sac before 8 weeks.
• Often found during fertility treatments or early pregnancy monitoring.
• May resolve with minimal symptoms.

Late-Diagnosed Blighted Ovum

• Identified when the gestational sac contains a yolk sac but still lacks an embryo, typically found between 8–12 weeks.
• May present with more pronounced symptoms of miscarriage (bleeding, pain).
• Often requires medical or surgical intervention for completion 2 4.

Clinical Course and Implications

• Early type is commonly encountered in ART (assisted reproductive technology) settings due to frequent and early ultrasounds 2.
• Later diagnoses might be more emotionally challenging, as women may have experienced weeks of typical pregnancy symptoms.

Causes of Blighted Ovum

The causes of blighted ovum are multifactorial, involving genetic, maternal, immunological, and occasionally environmental factors. While some risk factors are well-established, others remain speculative and under active investigation.

Risk Factor	Mechanism/Association	Notes/Details	Source(s)
Maternal age	Increased risk with age	Strongest known risk	1 2
Genetic defects	Chromosomal abnormalities, gene imprinting errors	Key driver in embryo non-development	1 2
Immune factors	Human leukocyte antigen-E, NK cells	15% of cases immunological	3
ART factors	Higher with blastocyst transfer	Possibly due to imprinting errors	2
Hormonal/ovulatory	Suboptimal ovum from ovulatory disorders	Follicular phase prolongation, luteal phase defects	1
Environmental	Consanguinity, malnutrition, infections	Less clearly established	1

Table 3: Causes of Blighted Ovum

Exploring the Causes

Maternal Age

Advancing maternal age is the most consistent risk factor for blighted ovum. The risk increases sharply for women over 35, likely due to higher rates of chromosomal abnormalities in ova 1 2.

Genetic and Chromosomal Factors

• Most blighted ova are caused by chromosomal errors that prevent embryonic development.
• Gene imprinting errors, which may be more common in ART cases (especially with blastocyst transfer), can disrupt early embryo development 2.
• In rare cases, familial patterns suggest a possible hereditary predisposition 1.

Immune System Dysfunction

• Around 15% of cases are linked to immune abnormalities, particularly involving Human Leukocyte Antigen-E and natural killer (NK) cells 3.
• These immune disruptions may prevent proper implantation or early embryonic development.

ART and Embryo Transfer Methods

• The use of assisted reproductive technologies, such as IVF, can increase the incidence of blighted ovum, especially with blastocyst (day-5 embryo) transfers 2.
• This may relate to subtle genetic or epigenetic changes during embryo growth in vitro.

Ovulatory and Hormonal Disorders

• Disorders like prolonged follicular phase or an inadequate luteal phase may lead to developmentally compromised ova, predisposing to blighted ovum 1.

Environmental and Lifestyle Factors

• Factors such as malnutrition, consanguinity, certain infections, and possibly even oral contraceptive use have been suggested, but their roles are less clear 1.

Treatment of Blighted Ovum

Once a blighted ovum is diagnosed, several treatment options are available. The choice depends on the patient’s preferences, medical situation, and timing of diagnosis. Management generally aims to safely complete the pregnancy loss and support emotional recovery.

Treatment	Method	Efficacy/Considerations	Source(s)
Expectant	Natural miscarriage	Non-invasive; may take time	4
Medical	Misoprostol, methotrexate	Effective, more rapid, some side effects	4 5
Surgical	Dilation & curettage (D&C)	Immediate, for incomplete/failed medical management	5

Table 4: Treatment Options

Treatment Approaches

Expectant Management (Watchful Waiting)

• In many cases, the body will expel the pregnancy tissue naturally.
• This approach is suitable for women with mild symptoms and no infection or heavy bleeding.
• Some may find the waiting period emotionally taxing.

Medical Management

• Misoprostol: A prostaglandin medication, misoprostol induces uterine contractions to expedite expulsion.
  • A study showed that 400 micrograms of intravaginal misoprostol significantly increases complete abortion rates compared to placebo (63% vs 18.5%) 4.
  • Side effects include lower abdominal pain (74.1%) and fever (14.8%), which are more common than with placebo 4.
• Methotrexate: Used in rare or special cases (e.g., when surgical access is difficult due to uterine anomalies).
  • Administered via intrauterine injection, methotrexate has been shown to induce complete abortion in select cases 5.
  • Monitoring is essential due to potential systemic effects.

Surgical Management

• Dilation and Curettage (D&C):
  • Recommended for women with heavy bleeding, signs of infection, or failed medical/expectant management.
  • Provides immediate resolution and allows for tissue analysis if needed 5.

Emotional Support and Counseling

• All women experiencing a blighted ovum should be offered emotional support and clear information about recurrence risks and future fertility.
• Most women go on to have healthy pregnancies after a blighted ovum.

Conclusion

A blighted ovum is a common, but often misunderstood, cause of early pregnancy loss. Understanding the symptoms, types, causes, and treatment options can empower women and families to make informed decisions during a challenging time.

Summary of Main Points:

• Symptoms: Early signs mimic healthy pregnancy; later, loss of symptoms, bleeding, and pain may occur 2 4.
• Types: Distinguished by timing—early (empty sac) vs. late (sac with yolk sac, no embryo) 2 4.
• Causes: Multifactorial—maternal age, genetic errors, immune dysfunction, ART factors, and possibly environmental influences 1 2 3.
• Treatment: Includes expectant management, medical (misoprostol, methotrexate), and surgical (D&C), with the choice tailored to the patient’s needs and clinical picture 4 5.

While a blighted ovum can be distressing, most women recover fully and retain the ability to conceive in the future. Compassionate care, accurate information, and support are vital for navigating this experience with hope and resilience.