Hydatidiform Mole: Causes, Symptoms, and Treatment
Medically reviewed by Harsha Moole, MD, Internal Medicine. Last reviewed: October 23, 2026.
What kind of doctor treats Hydatidiform Mole?
An obstetrician-gynecologist (an OB-GYN, a doctor who cares for pregnancy and the female reproductive system) usually treats a hydatidiform mole. If it becomes cancer, a gynecologic oncologist (a doctor for cancers of the female organs) may join the team. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What is a hydatidiform mole?
A hydatidiform mole is a rare growth inside the womb (uterus). It forms at the start of a pregnancy. It is also called a molar pregnancy. It is a type of gestational trophoblastic disease (GTD). GTD is a group of pregnancy-related conditions that develop inside the uterus. The placenta is the organ that feeds the developing baby (fetus) during pregnancy.
There are two types of molar pregnancy. A complete mole has an abnormal placenta and no fetus. A partial mole has an abnormal placenta and some fetal development. On ultrasound, the mass often looks like grapes because it holds many small cysts, which are fluid-filled sacs. Most hydatidiform moles are noncancerous, which means benign.
Symptoms
Until symptoms appear, a molar pregnancy can seem like a normal pregnancy.
- Vaginal bleeding during the first 3 months of pregnancy.
- Severe nausea and vomiting.
- A uterus that is bigger or smaller than usual.
- Pain or pressure in the pelvis.
- Signs of an overactive thyroid, such as a rapid heart rate.
- Early signs like preeclampsia, which are high blood pressure and swelling in the feet, ankles, and legs.
Many of these signs can also be caused by other conditions.
Causes and who gets it
A molar pregnancy results from abnormal fertilization of the egg. A complete mole forms when sperm fertilizes an egg that does not contain the mother's DNA. A partial mole forms when sperm fertilizes a normal egg. The fertilized egg has two sets of DNA from the father. A mole is more likely in older women. Being pregnant before age 20 or after age 35 raises the risk. A past mole is also a risk factor. There is no way to prevent a molar pregnancy.
About 15% of cases can become invasive. These moles can grow deep into the wall of the uterus and cause bleeding or other complications. In very few cases of complete mole, the mole turns into a choriocarcinoma, which is a fast-growing cancer.
How doctors diagnose it
Your provider will do a pelvic exam. It may look like a normal pregnancy. However, the size of the womb may be abnormal and there may be no heart sounds from the baby. A pregnancy ultrasound will show a snowstorm appearance with an abnormal placenta. A blood test measures hCG, a hormone made during pregnancy.
Doctors may also order other tests, such as:
- A chest x-ray.
- A CT or MRI of the belly (abdomen).
- A complete blood count.
- Blood clotting tests.
- Kidney and liver function tests.
Treatment
Treatment removes the abnormal tissue. A dilation and curettage (D&C) will most likely be suggested. In a D&C, the opening of the uterus is widened and the material inside is removed with a small vacuum-like device. A D&C may also be done with suction. This is called suction aspiration. Older women who do not want future pregnancies may choose a hysterectomy, which is surgery to remove the uterus.
After surgery, blood tests for beta-hCG are done every week until the level returns to normal. Patients also have follow-up doctor visits monthly for up to 6 months. If the level stays high or goes up, the mole may not be fully gone and may have become cancer. For disease that remains after surgery, treatment is usually chemotherapy.
Treatment is usually successful. Very rarely, a partial molar pregnancy can continue. These are very high-risk pregnancies.
When to see a doctor
Check with your doctor about vaginal bleeding that is not related to your period. After treatment, close follow-up with your provider is important. Call 911 or go to the emergency room if you have bleeding that will not stop, fainting or loss of consciousness, severe belly pain or pressure, or trouble breathing.
How a direct primary care or concierge doctor fits in
A direct primary care doctor charges a flat monthly fee instead of billing insurance, while a concierge doctor usually charges more and often works alongside insurance. Such a doctor can do an early evaluation and order basic tests. After a molar pregnancy, they can help you keep up with follow-up visits and coordinate with an OB-GYN.
Common questions
Is a hydatidiform mole cancer?
No, most hydatidiform moles are not cancer. Some can become invasive, and in very few cases of complete mole a fast-growing cancer called choriocarcinoma develops. Treatment is usually successful.
Can a molar pregnancy be prevented?
No, there is no way to prevent a molar pregnancy.
How long should I wait before trying to get pregnant again?
Wait 6 to 12 months after treatment. Avoid pregnancy and use a reliable contraceptive in that time. Women who get pregnant too soon after a molar pregnancy are at high risk of having another molar pregnancy.
Will I need tests after treatment?
Yes, you will need follow-up tests. Blood tests for beta-hCG are done every week until the level returns to normal. You also have follow-up doctor visits monthly for up to 6 months.
Sources
- MedlinePlus - Hydatidiform mole
- National Cancer Institute - Gestational Trophoblastic Disease Treatment
- MedlinePlus - Gestational trophoblastic disease
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
