What is Gestational Trophoblastic Disease?
GTD is the degeneration and abnormal proliferation of the trophoblastic villi. The cells fill with clear fluid and take on the look of grape-like vesicles.
Pathophysiology
A partial mole is almost always triploid, with 69 chromosomes, usually from two sperm fertilizing a single ovum, and a nonviable fetus may be present. A complete mole is diploid, with 46 chromosomes that are entirely paternal, typically from one sperm fertilizing an empty ovum and then duplicating its DNA, and no fetus develops (Hydatidiform Mole, StatPearls). Either way the trophoblastic villi proliferate rapidly into fluid-filled, grape-like vesicles.
Risk Factors
GTD occurs in 1 of every 1,500 pregnancies. Watch for these:
- Low protein intake. Protein is needed to build the trophoblastic villi.
- Age over 35. Pregnancy past 35 carries higher risk for H-mole.
- Asian ethnicity. Higher incidence linked to genetics.
- Blood group A woman with a blood group O partner. This pairing is associated with H-mole.
Signs and Symptoms
- Uterus expanding faster than expected. The trophoblast cells proliferate so fast the uterus hits its growth landmarks early.
- Very high serum or urine hCG. Rapidly growing trophoblast cells pump out large amounts of hCG.
- Vaginal bleeding. If the H-mole is still undetected by the 16th week, it announces itself with bleeding, often with clear fluid-filled vesicles.
Diagnostic Tests
- Pregnancy test. Confirms pregnancy but does not pin down the H-mole.
- Urine or serum hCG. A very high result points to an H-mole.
- Ultrasound. Shows dense grape-like vesicles in a snowflake pattern, clear fluid instead of an embryo.
Medical Management
- Methotrexate. A prophylactic course attacks the rapidly growing trophoblastic cells.
- Dactinomycin. Added once metastasis occurs.
Surgical Management
- Suction curettage. The definitive treatment, evacuating the mole before it causes further complications.
After evacuation, serial beta-hCG levels track the response: the NCI recommends weekly beta-hCG testing until levels return to normal, then monthly follow-up for up to six months. A level that plateaus or rises signals gestational trophoblastic neoplasia and the need for chemotherapy. Reliable contraception during this window keeps a new pregnancy from masking a rising hCG (Gestational Trophoblastic Disease Treatment, NCI).
Nursing Management
Nursing Assessment
- Measure abdominal girth and fundal height against expected pregnancy landmarks.
- Watch for pregnancy-induced hypertension. With H-mole it shows up before the 20th week.
- Tell her to save every perineal pad with clots or passed tissue.
Nursing Diagnosis
- Grieving related to loss of pregnancy as evidenced by anger and social detachment.
Nursing Interventions
- Measure abdominal girth and fundal height for baseline uterine growth.
- Help her collect a urine specimen for hCG.
- Save all pads used during bleeding to check for clots and tissue.
- Give her an open, trusting environment so she can express what she feels.
- Answer her questions honestly.
- Reassure her this is not her fault to ease guilt and self-blame.
Evaluation
- She expresses her feelings.
- She acknowledges the situation and seeks appropriate help.
- She begins looking forward, one step at a time.
Losing a pregnancy is one of the hardest things a patient will face. Your knowledge, steadiness, and presence are what get her through it.
Frequently Asked Questions
What is gestational trophoblastic disease? A group of conditions in which trophoblastic cells, the cells that normally form the placenta, grow abnormally. It ranges from benign hydatidiform (molar) pregnancy to malignant gestational trophoblastic neoplasia.
What is the difference between a complete and a partial mole? A complete mole is diploid (46 chromosomes, all paternal) with no fetus. A partial mole is triploid (69 chromosomes) and may contain nonviable fetal tissue. Both produce grape-like swollen villi (StatPearls).
What are the warning signs? Vaginal bleeding in early pregnancy, a uterus larger than expected for dates, very high beta-hCG, severe nausea and vomiting, and an ultrasound showing a "snowstorm" pattern with no fetal heartbeat.
How is it treated? Suction curettage evacuates the mole. Persistent or malignant disease is treated with chemotherapy such as methotrexate, with dactinomycin added if it spreads.
Why is hCG followed after treatment? Beta-hCG is a sensitive marker of remaining trophoblastic tissue. The NCI recommends weekly testing until it normalizes, then monthly follow-up for up to six months, because a rising level means the disease has progressed to neoplasia.
Can a woman get pregnant again after a molar pregnancy? Yes. Most women go on to have normal pregnancies, but she should use reliable contraception until hCG monitoring is complete so a new pregnancy does not hide a recurrence.