Gestational Trophoblastic Disease: Types, Symptoms, Diagnosis and Treatment — Overview, Diagnosis & Treatment Options | MyMedicPlus

Gestational trophoblastic disease (GTD) encompasses a spectrum of pregnancy-related tumors originating from the trophoblastic cells of the placenta. The spectrum ranges from benign hydatidiform moles (complete and partial) to malignant gestational trophoblastic neoplasia (GTN), which includes invasive mole, choriocarcinoma, placental site trophoblastic tumor (PSTT), and epithelioid trophoblastic tumor (ETT). Hydatidiform moles are the most common form: complete moles (46,XX or 46,XY, entirely paternal genome) carry a 15–20% risk of progressing to GTN, while partial moles (69,XXX or 69,XXY, triploid) carry a 1–5% risk. Choriocarcinoma can follow any type of pregnancy — molar (50%), normal term pregnancy (25%), ectopic pregnancy (3%), or spontaneous abortion (25%). GTD is characterized by extraordinarily high cure rates even in metastatic disease because of exquisite sensitivity to chemotherapy. Complete remission is achieved in >99% of low-risk GTN and >90% of high-risk metastatic GTN with cisplatin-based combination chemotherapy. Fertility preservation is achievable in the majority of patients.

Complete hydatidiform moles arise from fertilization of an anucleate ('empty') egg by one or two sperm, resulting in a diploid, entirely paternal genome (androgenesis). Partial moles result from dispermic fertilization of a normal oocyte, producing a triploid genome. Advanced maternal age (>35 years: relative risk ×2; >40 years: RR ×5–10) and prior molar pregnancy (1–2% risk of recurrence) are the strongest risk factors for molar pregnancy. A history of two prior molar pregnancies elevates recurrence risk to ~20%. Biparental complete moles — a hereditary form caused by NLRP7 or KHDC3L germline mutations — cause recurrent complete moles without malignant potential. Nutritional deficiencies (carotene, folate) and Asian or Latin American ethnicity are associated with higher molar pregnancy incidence in epidemiological studies. Prior GTN treatment does not impair subsequent normal pregnancy outcomes if hCG has normalized.

Complete hydatidiform moles classically present with vaginal bleeding in the first trimester, a uterus larger than dates, absence of fetal heart sounds, and a markedly elevated serum hCG (often >100,000 mIU/mL). Hyperemesis gravidarum due to extreme hCG elevation occurs in 10–25%. Hyperthyroidism (hCG-mediated thyroid stimulation) causes palpitations, tremor, and weight loss in ~5%. Theca-lutein ovarian cysts from excessive hCG stimulation cause bilateral adnexal fullness. Early-onset preeclampsia before 20 weeks should prompt molar pregnancy evaluation. Partial moles often present identically to missed or incomplete abortion and are diagnosed post-operatively on histology. GTN post-mole is diagnosed by hCG plateau or rise on surveillance rather than symptoms. Metastatic choriocarcinoma may present with pulmonary (cough, hemoptysis), vaginal (bleeding, mass), cerebral (headache, focal deficit, seizure), or hepatic involvement.

Pelvic ultrasound reveals the classical 'snowstorm' appearance of a complete mole — heterogeneous intrauterine mass with multiple anechoic spaces replacing normal placenta — in 75% of cases. Serum quantitative hCG is markedly elevated. Complete blood count, thyroid function, liver and renal function tests, and chest X-ray complete the initial evaluation. Uterine curettage provides pathological diagnosis; histopathology with p57 immunostaining (absent in complete moles, which lack a maternal genome) distinguishes complete from partial moles. FIGO 2000 staging uses anatomical sites (I–IV) combined with the WHO prognostic scoring system (0–6: low-risk; ≥7: high-risk) to guide treatment intensity. Score integrates age, antecedent pregnancy, interval from index pregnancy, pre-treatment hCG level, largest tumor size, site of metastases, number of metastases, and prior chemotherapy. MRI brain is required to evaluate for cerebral metastases in high-risk GTN.

Suction curettage under ultrasound guidance is the standard evacuation method for hydatidiform moles; hysterotomy is avoided due to increased complications. A single prophylactic dose of methotrexate may be given at evacuation in high-risk cases. Post-molar hCG surveillance — weekly until normalized, then monthly for 3–6 months — is mandatory to detect GTN early. Contraception during surveillance prevents confounding hCG elevation from a new pregnancy. Low-risk GTN (WHO score 0–6) is treated with single-agent methotrexate (50 mg/m² IM weekly or MTX/folinic acid) or actinomycin-D, achieving cure rates of 85–95%. High-risk GTN (WHO score ≥7 or FIGO Stage III–IV) requires combination chemotherapy: EMA-CO (etoposide, methotrexate, actinomycin-D, cyclophosphamide, vincristine) achieves remission in ~80% of patients. EMA-EP or TE/TP are salvage regimens. PSTT and ETT are less chemosensitive; hysterectomy is the primary treatment with adjuvant EP-EMA.

Gestational trophoblastic disease carries some of the highest cure rates of any malignancy. Hydatidiform mole, when managed with appropriate evacuation and hCG surveillance, has essentially no mortality from the mole itself. Low-risk GTN (WHO score 0–6) achieves complete remission in 99% of patients with single-agent methotrexate or actinomycin-D chemotherapy. High-risk GTN (WHO score ≥7) treated with EMA-CO achieves remission in approximately 85% of patients as first-line therapy, with salvage EMA-EP achieving remission in most remaining cases — overall cure rates for high-risk GTN exceed 90–95%. Placental site trophoblastic tumor and epithelioid trophoblastic tumor have less favorable outcomes than choriocarcinoma; hysterectomy is the primary treatment and chemosensitivity is lower. Key prognostic factors include the WHO score (incorporating hCG level, antecedent pregnancy type, interval, metastatic sites, and number of metastases), FIGO stage, and prior chemotherapy. Fertility is preserved in most patients — subsequent pregnancies after GTN treatment are not associated with increased fetal anomaly rates. Cerebral and hepatic metastases are adverse prognostic features requiring more intensive treatment. Sustained hCG normalization after treatment completion signifies remission; hCG monitoring for 12 months after treatment completion confirms durable cure.

There are no proven strategies to prevent hydatidiform moles. Women with prior molar pregnancy should wait 6–12 months after hCG normalization before attempting the next pregnancy — the risk of recurrent molar pregnancy in the subsequent pregnancy is 1–2%, compared to the baseline 1 per 1,000. Combined oral contraceptive pills may be used during the surveillance period as they do not affect hCG levels. Recurrent complete moles (three or more) should prompt genetic testing for NLRP7 or KHDC3L mutations and referral to a specialist center. All cases should be registered with a national GTD surveillance program (e.g., Charing Cross in the UK, or state registry in the US) where available, as centralized follow-up significantly improves outcomes.

Any woman in the first trimester with vaginal bleeding and uterus-size-date discrepancy should have immediate pelvic ultrasound and serum hCG to exclude molar pregnancy. Markedly elevated hCG (>100,000 mIU/mL) in early pregnancy strongly suggests complete mole and warrants urgent referral to a gynecologic oncologist or specialist GTD center. After molar evacuation, patients must not miss hCG surveillance appointments — rising or plateauing hCG on three consecutive weekly measurements or any rise on two measurements indicates GTN requiring immediate treatment. Women with unexplained hemoptysis, neurological symptoms, or vaginal bleeding after any pregnancy (including abortion or ectopic) should have a serum hCG measured to exclude choriocarcinoma, which can present months to years after the antecedent pregnancy.