Hydatidiform Mole

A hydatidiform mole, also known as a molar pregnancy, is a rare mass or growth that forms inside the womb during early pregnancy.

Causes and Risk Factors

A hydatidiform mole occurs when there is an abnormal fertilization of the egg, resulting in an overgrowth of trophoblast cells, which would normally develop into the placenta. The exact cause is not known, but it is thought to be related to genetic errors during fertilization.

  • Most hydatidiform moles are sporadic and occur by chance.
  • A woman's risk of having a molar pregnancy increases if she:
    • Is over 35 years old
    • Has had a previous molar pregnancy
    • Has a family history of molar pregnancies
    • Is of Asian descent

Symptoms

The symptoms of a hydatidiform mole can vary, but may include:

Types of Hydatidiform Moles

There are two main types of hydatidiform moles:

  • Complete mole: This type of mole occurs when a sperm fertilizes an empty egg, resulting in a growth with no fetal tissue.
  • Partial mole: This type of mole occurs when two sperm fertilize a normal egg, resulting in a growth with some fetal tissue, but it is usually severely abnormal and cannot survive.

Diagnosis

A hydatidiform mole is typically diagnosed during an ultrasound examination, which can show the characteristic "snowstorm" appearance of the mole. Other diagnostic tests may include:

Treatment

The primary treatment for a hydatidiform mole is surgical removal of the mole, usually through a procedure called a dilation and curettage (D&C). In some cases, other treatments may be necessary, such as:

Complications

A hydatidiform mole can increase a woman's risk of developing certain complications, including:

  • Gestational trophoblastic neoplasia (GTN), a type of cancer that develops from the trophoblast cells
  • Placental site trophoblastic tumor (PSTT), a rare type of cancer that develops in the uterus
  • Choriocarcinoma, a type of cancer that develops from the trophoblast cells

Follow-up Care

After treatment for a hydatidiform mole, it is essential to follow up with regular check-ups and blood tests to monitor for any signs of complications or recurrence. This may include:

  • Regular hCG blood tests to ensure that the levels return to normal
  • Ultrasound examinations to check for any remaining tissue or cancer cells
  • Annual check-ups with a healthcare provider to monitor for any signs of recurrence or complications

Frequently Asked Questions (FAQs)

What is a hydatidiform mole?
A rare mass or growth that forms inside the womb during pregnancy.

What causes a hydatidiform mole?
Abnormal fertilization of an egg, often due to extra paternal chromosomes.

What are the symptoms of a hydatidiform mole?
Vaginal bleeding, severe nausea, and rapid uterine growth.

How is a hydatidiform mole diagnosed?
Ultrasound and blood tests for human chorionic gonadotropin (hCG) levels.

Is a hydatidiform mole cancerous?
Usually not, but can develop into cancer in some cases.

What is the treatment for a hydatidiform mole?
Surgical removal of the mole, often by dilation and curettage (D&C).

Can a woman still get pregnant after having a hydatidiform mole?
Yes, but close follow-up is needed due to increased risk of recurrence.

What are the risks associated with a hydatidiform mole?
Bleeding, infection, and potential development of gestational trophoblastic disease (GTD).

How common is a hydatidiform mole?
Occurs in about 1 in every 1,000 pregnancies.

Can a hydatidiform mole be prevented?
No, as it is often caused by random genetic errors during fertilization.

Article last updated on: 25th June 2025.
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