Overview, Causes, & Risk Factors

A molar pregnancy occurs when a fetus is not able to fully form in the uterus. Instead, the fetal tissue becomes a tumor.

What is going on in the body?

In the US, a molar pregnancy occurs in 1 out of every 2,000 pregnancies. In this condition, fetal cells have an abnormal genetic makeup and form a tumor. This tumor, or "mole," can grow and even spread to other parts of a mother's body. In some cases, the mole may turn into a more dangerous cancer called choriocarcinoma.

What are the causes and risks of the condition?

In this condition, abnormal fetal tissue inside a woman's uterus forms a tumor. The exact reason this occurs is not known. Common risk factors for this condition include:

Symptoms & Signs

What are the signs and symptoms of the condition?

Common symptoms of this condition may include:

Diagnosis & Tests

How is the condition diagnosed?

Diagnosis begins with a history and physical exam. There is usually a history of a recent pregnancy, whether or not a child was born. A blood test is done to measure the level of HCG, the "hormone of pregnancy." In a molar pregnancy, the level of HCG becomes too high because of the abnormal fetal tissue.

If the level of HCG is abnormally high, an ultrasound can help locate and confirm the tumor. A chest x-ray or MRI or CT scan of different parts of the body may be done if the healthcare provider suspects that the tumor has spread to other organs.

Prevention & Expectations

What can be done to prevent the condition?

Women are advised to get enough folate, carotene, and protein in their diet before becoming pregnant. This may decrease the risk of this condition.

Early diagnosis improves the chance of cure, though it cannot prevent this condition. Any woman with abnormal vaginal bleeding or other unusual symptoms after pregnancy should see her healthcare provider.

What are the long-term effects of the condition?

I n most cases, treatment results in a cure and there are few long-term effects. However, the tumor can spread to other areas of the body, which may result in organ damage and even death.

What are the risks to others?

This condition is not contagious and poses no risk to others.

Treatment & Monitoring

What are the treatments for the condition?

In most cases, the main treatment is a procedure called a dilation and curettage (D&C). This involves removing all the contents of the inside of the uterus with a special tool. In women who do not want any more children, a hysterectomy, or the removal of the uterus, may be advised.

If the tumor has spread to other areas of the body, chemotherapy and sometimes radiation therapy is usually advised.

What are the side effects of the treatments?

If a hysterectomy or a D&C is done, the side effects may include bleeding, infection, and scarring of the uterus. Chemotherapy can cause stomach upset, nausea, weakness, and other side effects.

What happens after treatment for the condition?

A woman is advised to take it easy for a few days after a D&C. A hysterectomy usually requires a few weeks of recovery. The woman should be alert for any unusual bleeding after surgery.

After all types of treatment, the level of HCG in the blood is checked regularly to make sure it returns to normal. If the level of HCG stays high or becomes high again in the future, this may mean that the tumor has spread or come back. Birth control should be used for at least 1 year after treatment. This is because pregnancy, by raising the level of HCG, can make it hard to detect if the tumor has come back.

How is the condition monitored?

Regular chest x-rays and pelvic exams are often advised. Any new or worsening symptoms should be reported to the healthcare provider.