Are there any complications of a molar pregnancy?

The majority of hydatidiform moles, also known as molar pregnancies, are very treatable, whether through a dilation and curettage (D&C) or a more permanent procedure like a hysterectomy. The success rates of these procedures are quite high. However, women should know that possible complications are associated with molar pregnancies, and also that women who have a molar pregnancy may be at greater risk of certain future health conditions.

Persistent gestational trophoblastic disease

A molar pregnancy is one of a few different conditions under the umbrella of gestational trophoblastic disease (GTD). Most of the time after treatment to remove a molar pregnancy, the body will get rid of any molar tissue that remains in the uterus. However, for some women, molar tissue remains and continues to grow. This is known as persistent gestational trophoblastic disease. Persistent GTD occurs in roughly one out of every five women who experience a molar pregnancy. It is more common after a complete molar pregnancy than a partial one.

When the remaining molar tissue grows into, or invades, the tissue surrounding the uterus, gestational trophoblastic neoplasm (GTN) has occurred. GTN can be dangerous, and it is considered a malignancy because it has the potential to spread to other parts of the body. To make sure that the tissue isn’t still growing, your healthcare provider will regularly measure your hCG level and check to make sure it is decreasing over time. A sign of GTN is high hCG levels after the removal of molar tissue.

If it’s determined that a woman has GTN, the condition requires additional treatment, but it can usually be treated with chemotherapy or a hysterectomy, depending on what the provider and the woman decide is best.

Invasive mole

Invasive moles occur when molar tissue remains in the uterus after treatment and grows into the uterine muscle wall. Most of the time, invasive moles will remain localized to the uterus, but invasive moles do have the ability to spread to other parts of the body, which is why they require additional treatment.


Choriocarcinoma is a cancerous and rarer type of GTD, and while they can develop spontaneously, half of all cases of choriocarcinoma occur after a molar pregnancy. The condition grows quickly and can spread to other organs in the body, so it needs to be treated right away. Cancer drugs are usually used to treat choriocarcinoma.

Knowing your risk

It’s important to understand that these complications are uncommon, and they don’t affect the majority of women who experience a molar pregnancy. However, knowing the possible complications can help you prepare for your appointments and understand why your provider takes certain measures to monitor things like your hCG levels. If you have any questions about possible risks of GTD, make sure to ask your provider to tell you more about them, and how they may or may not relate to your health.

  • Mayo Clinic Staff. “Molar Pregnancy: Complications.” MayoClinic. Mayo Foundation for Medical Education and Research, Oct 24 2014. Web.
  • “What is gestational trophoblastic disease?” Cancer. American Cancer Society, Feb 9 2016. Web.
  • “Gestational Trophoblastic Disease.” MedlinePlus. US National Library of Medicine, Jun 11 2014. Web.
  • Ross Berkowitz, et al. “Gestational trophoblastic neoplasia: Epidemiology, clinical features, diagnosis, staging, and risk stratification.” Uptodate. UptoDate, Inc., Jan 5 2015. Web.
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