ConditionWomen's & pregnancy health
Gestational Trophoblastic Disease (GTD)
Gestational trophoblastic disease (GTD) is a group of rare conditions in which cells that normally form the placenta (trophoblast cells) grow abnormally after conception. The most common form is a molar pregnancy (hydatidiform mole), which cannot develop into a healthy baby. Less often, abnormal tissue persists or becomes cancerous, called gestational trophoblastic neoplasia (GTN), which includes choriocarcinoma. GTD is usually found because of bleeding or on an early ultrasound, is tracked with hCG blood tests, and is almost always curable.
Also called: GTD, molar pregnancy, hydatidiform mole, gestational trophoblastic neoplasia (GTN), choriocarcinoma
At a glance
- What it is
- Abnormal growth of placenta-forming cells after conception.
- Main types
- Complete and partial molar pregnancy (benign), and GTN: invasive mole, choriocarcinoma and rarer tumors.
- Signs
- Vaginal bleeding in early pregnancy, severe nausea, a uterus larger than expected, very high hCG.
- Treatment
- Suction removal of molar tissue, weekly hCG monitoring, chemotherapy if GTN develops.
- Outlook
- Cure rates are close to 100 percent for most forms.
When to get help
Call 911 or go to the ER
- Heavy vaginal bleeding, soaking a pad an hour, or feeling faint in early pregnancy
- Severe headache, vision changes, chest pain or breathlessness in early pregnancy or after a molar pregnancy
See a doctor within a day or two
- Vaginal bleeding or passing grape-like tissue in early pregnancy
- Severe nausea and vomiting with inability to keep fluids down
- New or ongoing bleeding, cough, or headaches in the months after a molar pregnancy or any pregnancy
Book a routine appointment
- Missing scheduled hCG blood tests after a molar pregnancy
- Planning a new pregnancy after GTD: discuss timing with your doctor
Types of gestational trophoblastic disease
| Type | What it is | Cancer risk |
|---|---|---|
| Complete mole | An egg without maternal genetic material is fertilized. Only abnormal placental tissue grows, no fetus | About 15 to 20 percent develop GTN |
| Partial mole | An egg is fertilized by two sperm. Abnormal placenta with some fetal tissue that cannot survive | About 1 to 5 percent develop GTN |
| Invasive mole | Molar tissue grows into the uterine wall | Malignant (GTN) |
| Choriocarcinoma | A fast-growing cancer that can follow a molar pregnancy, miscarriage, ectopic or normal pregnancy, and spread to lungs, liver or brain | Malignant, highly curable |
| Placental site and epithelioid trophoblastic tumors | Rare, slow-growing tumors | Malignant, often treated with surgery |
Symptoms
Molar pregnancy
- Vaginal bleeding in the first trimester, sometimes with dark brown discharge or grape-like cysts
- Severe nausea and vomiting (hyperemesis gravidarum)
- A uterus larger than expected for the stage of pregnancy (more often with complete moles)
- Pelvic pressure or pain
- Rarely, early preeclampsia before 20 weeks, or an overactive thyroid caused by very high hCG
- Many moles are now found on early ultrasound before symptoms appear
GTN
- Irregular vaginal bleeding after a pregnancy has ended
- hCG levels that plateau or rise after a molar pregnancy
- Symptoms from spread: cough or coughing blood (lungs), headaches or seizures (brain), belly pain (liver)
Causes and risk factors
Molar pregnancies result from an error at fertilization. Risk factors include:
- Age under 20 or over 35 to 40
- A previous molar pregnancy
- Previous miscarriages
- Some ethnic backgrounds and regions with higher rates
Most people who have a molar pregnancy have no identifiable risk factor and did nothing to cause it.
Diagnosis
- hCG blood test: levels are often much higher than expected.
- Pelvic ultrasound: a complete mole may show a "snowstorm" or cluster-of-grapes pattern with no fetus. Partial moles are harder to see.
- Tissue examination: confirms the diagnosis after removal.
- For GTN: rising or plateauing hCG, chest X-ray or CT, and sometimes MRI of the brain, used for staging and a risk score that guides treatment.
Treatment
Molar pregnancy
- Suction dilation and curettage (D&C): removes the molar tissue. Medicines alone are not recommended for evacuating a mole.
- Hysterectomy: an option for people who do not want future pregnancies, though hCG monitoring is still needed.
- Rh immunoglobulin if Rh-negative.
hCG follow-up
After a molar pregnancy, hCG is measured every 1 to 2 weeks until it is undetectable, then monthly for a period, often 1 to 3 months for partial moles and up to around 3 to 6 months for complete moles, depending on guidelines. Reliable contraception is recommended during follow-up so that a new pregnancy does not confuse the results. Hormonal contraception is considered safe.
Gestational trophoblastic neoplasia
- Low-risk GTN: single-agent chemotherapy, usually methotrexate or actinomycin D, cures nearly everyone.
- High-risk GTN: combination chemotherapy, sometimes with surgery or radiation, still achieves high cure rates.
- Placental site and epithelioid tumors: usually treated with hysterectomy.
Outlook
GTD is one of the most curable gynecologic conditions. Nearly all molar pregnancies are cured by evacuation and follow-up. Low-risk GTN has cure rates near 100 percent, and most high-risk cases are also curable. Fertility is usually preserved, and future pregnancies are typically healthy, though early ultrasound is recommended in the next pregnancy because the risk of another mole is slightly higher.
Emotional impact
A molar pregnancy is a pregnancy loss, often combined with worry about cancer and months of blood tests. Grief, anxiety and frustration are common. Support groups and counseling can help.
Frequently asked questions
What is a molar pregnancy?
A molar pregnancy is a type of gestational trophoblastic disease in which an error at fertilization causes abnormal placental tissue to grow instead of a normal pregnancy. In a complete mole there is no fetus. In a partial mole there may be some fetal tissue, but it cannot survive.
What are the symptoms of a molar pregnancy?
The most common symptom is vaginal bleeding in the first trimester. Others include severe nausea and vomiting, a uterus that is larger than expected, pelvic pressure and, rarely, early high blood pressure or thyroid symptoms. Many are now found on routine early ultrasound.
Why is hCG monitored after a molar pregnancy?
Tracking hCG shows whether all abnormal tissue has gone. hCG should fall steadily to undetectable levels. If it plateaus or rises, it can signal gestational trophoblastic neoplasia, which needs treatment, usually chemotherapy. Monitoring catches this early, when it is almost always curable.
Can you get pregnant after gestational trophoblastic disease?
Yes. Most people can have healthy pregnancies after GTD, including after chemotherapy. Doctors usually advise waiting until hCG follow-up is complete, and recommend an early ultrasound in the next pregnancy, because the chance of another molar pregnancy is slightly higher.
Sources
This guide was written from current patient and clinical guidance, including:
- American College of Obstetricians and Gynecologists (ACOG): Molar pregnancy; Gestational trophoblastic disease (Practice Bulletin)
- National Cancer Institute: Gestational Trophoblastic Disease Treatment (PDQ)
- American Cancer Society: Gestational trophoblastic disease
- FIGO Cancer Report: Diagnosis and management of gestational trophoblastic disease
- Royal College of Obstetricians and Gynaecologists (RCOG): Management of gestational trophoblastic disease