Educational draft · awaiting clinical reviewThe full textbook explains uncertainty but does not replace live national or local guidance, specialist advice, or current prescribing information.
Persistent gestational trophoblastic neoplasia
Obstetrics and gynaecology · UK scope · Sources checked 27 Aug 2026 · Clinical review pending
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Bleeding or organ symptoms require immediate escalation
Major vaginal bleeding, haemoptysis, hypoxia, severe headache, focal neurology, seizures, right-upper-quadrant pain or shock in possible GTN may reflect highly vascular uterine or metastatic disease.
Action: Use ABCDE resuscitation, call senior gynaecology, oncology, anaesthesia and relevant critical specialists, avoid biopsy of a vascular metastasis, and contact the national GTD treatment centre urgently.
Overview
Recognise persistent gestational trophoblastic neoplasia from hCG and clinical signals, arrange specialist staging and support risk-adapted treatment with curative intent.
Gestational trophoblastic neoplasia describes malignant or potentially malignant trophoblast that persists or appears after pregnancy. Invasive mole usually follows a molar pregnancy and penetrates the myometrium. Choriocarcinoma lacks chorionic villi and can follow any gestation, spreading haematogenously to lungs, vagina, brain, liver and other sites. Placental-site trophoblastic tumour and epithelioid trophoblastic tumour produce less hCG relative to disease burden, behave differently and often require surgery. These entities belong in a national specialist service rather than a general gynaecological cancer pathway alone.
Most post-molar GTN is found before symptoms because central surveillance shows hCG no longer falling appropriately. FIGO 2026 defines a plateau as less than 10% rise or fall across four measurements over at least three weeks, a rise as more than 10% across three consecutive weekly measurements over at least two weeks, and histological GTN as gestational choriocarcinoma, placental-site trophoblastic tumour or epithelioid trophoblastic tumour; persistence beyond six months is not a FIGO criterion. Charing Cross retains centre-specific UK treatment triggers that include a rise in two consecutive serum samples, a plateau in three consecutive samples, hCG above 20,000 IU/L more than four weeks after evacuation, raised hCG at six months after individual review, heavy vaginal, gastrointestinal or intraperitoneal bleeding and specified metastases.
Practice
Two practice questions
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Obstetrics and gynaecologyOriginal SBA
Unsafe investigation in possible GTN
A patient with persistent hCG after molar pregnancy has a purple vaginal nodule and intermittent heavy bleeding. Which proposed investigation should be avoided before specialist discussion?
Sources and review status6 sources · checked 27 Aug 2026 · clinical review pending+
Sources
Sources and review status
National guidance is shown before implementation-dependent detail. Typical adult dose examples remain subject to patient factors, contraindications and the live BNF or specialist protocol. Source check completed 27 Aug 2026; clinical approval remains outstanding.
act on a transcription error or one assay: verify the dated series and involve the national centre that owns follow-up.
Persistent hCG has important alternatives. A new intrauterine or ectopic pregnancy can raise hormone normally. Retained non-molar products, recent exogenous hCG, pituitary hCG and heterophile-antibody assay interference can cause detectable results. Compare serum and urine, repeat using the specialist platform and take a careful sexual, contraception and pregnancy history. These checks should be prompt and should not delay emergency assessment when bleeding or organ symptoms suggest active disease.
The specialist team stages anatomical spread and calculates the FIGO 2026 risk score from seven factors: age, antecedent pregnancy, interval, pre-treatment hCG, largest tumour, metastatic site and number of metastases; previous chemotherapy has been removed from the score. Do not apply this score to PSTT or ETT: use anatomical stage plus the interval from antecedent pregnancy, with at least 48 months a poor prognostic factor for stages I–III and all stage IV disease poor prognosis. Low-risk assessment uses chest radiography and pelvic Doppler ultrasound or MRI. High-risk disease and any choriocarcinoma require contrast-enhanced CT of chest and abdomen plus contrast-enhanced MRI of brain and pelvis when available; if lung metastases at least 1 cm are found, brain and abdominopelvic cross-sectional imaging is required. Only lung lesions at least 1 cm count toward the risk score, and imaging and hCG should be obtained as close as possible to treatment because disease can grow rapidly. Avoid biopsy of a vascular vaginal, hepatic or other metastasis because torrential haemorrhage can result. Histology is not required when hCG criteria after a mole establish the diagnosis.
Low-risk disease, score 0–6, is usually curable with single-agent chemotherapy. Scores 5–6 need a further treatment check because FIGO 2026 identifies patients who may benefit from first-line multi-agent therapy: those with post-molar non-metastatic disease and pretreatment hCG at least 410,000 IU/L; post-molar metastatic disease or non-metastatic choriocarcinoma with hCG at least 150,000 IU/L; and metastatic choriocarcinoma with any raised hCG. In the absence of these additional risk factors, score 5–6 remains in the low-risk group and the specialist centre can use its single-agent pathway. Charing Cross commonly uses intramuscular methotrexate on alternate days with oral folinic-acid rescue, repeated after a rest interval. hCG is checked during treatment, and resistance is defined by an inadequate decline or renewed rise rather than by symptoms alone; specialist protocols then switch agent or regimen. Chemotherapy continues after hCG becomes normal, commonly for three further cycles or six weeks, to reduce relapse risk.
High-risk disease, score 7–12, usually receives multi-agent EMA-CO in a specialist centre. Reserve the ultra-high-risk label for a score of at least 13. Low-dose induction before combination treatment may be needed for ultra-high-risk disease and also for a high-risk score of 7–12 when critical brain, liver or extensive pulmonary burden makes rapid tumour breakdown especially dangerous. Surgery, embolisation, radiotherapy or intrathecal therapy is selected for bleeding, resistant foci or particular metastatic sites. PSTT and ETT are relatively chemoresistant, making hysterectomy central when disease is confined to the uterus.
Monitor hCG, blood counts, renal and liver function and regimen-specific toxicity throughout therapy. Methotrexate can cause mucositis, conjunctival or pleuritic symptoms and liver-test disturbance; multi-agent therapy carries broader marrow, infection, neuropathy and fertility risks. Patients should have a direct number for toxicity and bleeding. After treatment, the centre defines hCG follow-up and usually advises avoiding pregnancy for a specified period, commonly around 12 months after chemotherapy, so recurrence is not masked.
Prognosis after post-molar low-risk GTN is exceptionally good, and even high-risk disease is commonly curable. Communicate this without minimising cancer-related distress, treatment burden or pregnancy loss. Discuss contraception, ovarian function, future fertility, timing of conception and early imaging in the next pregnancy. Ensure the GP knows which symptoms and tests belong to the specialist plan and that incidental hCG testing elsewhere does not fragment surveillance.
Key points
GTN includes invasive mole, choriocarcinoma and rarer placental-site or epithelioid trophoblastic tumours; persistent disease is most often detected through abnormal hCG after molar evacuation.
Current FIGO 2026 GTN criteria are an hCG plateau of less than 10% rise or fall across four measurements over at least three weeks, an hCG rise of more than 10% across three consecutive weekly measurements over at least two weeks, or histological gestational choriocarcinoma, placental-site trophoblastic tumour or epithelioid trophoblastic tumour. Charing Cross also uses centre-specific UK treatment triggers, including hCG above 20,000 IU/L more than four weeks after evacuation and individually reviewed persistence at six months, alongside major bleeding and specified metastases.
GTN can follow a complete or partial mole, miscarriage, abortion, ectopic or term pregnancy, so persistent bleeding and hCG require obstetric-history review even months later.
Confirm pregnancy status and assay validity, then let the national centre direct imaging, FIGO anatomical stage and WHO prognostic scoring.
Scores of 0–6 remain the low-risk group, 7–12 are high risk and 13 or more are ultra-high risk. Scores 5–6 carry greater single-agent resistance, and FIGO 2026 identifies combinations of tumour type, metastases and pretreatment hCG for which patients may benefit from first-line multi-agent therapy despite the low-risk label.
Aetiology
01
Residual post-molar trophoblast
Invasive molar cells can remain within uterine muscle or vascular channels after evacuation and continue proliferating instead of undergoing spontaneous regression.
02
Gestational choriocarcinoma
Malignant trophoblast can arise after molar or non-molar pregnancy and spread early through blood vessels, often without an identifiable uterine mass.
03
Intermediate trophoblast tumours
PSTT and ETT arise from specialised implantation-site trophoblast, secrete relatively little hCG and show different chemotherapy sensitivity from invasive mole.
Pathophysiology
1
Myometrial invasion
Persistent trophoblast erodes uterine muscle and vessels, creating a hypervascular focus that causes irregular bleeding and can perforate or rupture.
2
Haematogenous dissemination
Choriocarcinoma readily enters the circulation and seeds lungs, vagina, brain, liver and other organs, where fragile tumour vessels may haemorrhage.
3
Continuing hormone secretion
Viable syncytiotrophoblast releases hCG, making serial concentration a highly sensitive measure of burden and treatment response in most GTN subtypes.
4
Chemotherapy selection pressure
Sensitive cell populations fall with treatment, while an inadequate hCG response can reveal resistant clones requiring a timely change in regimen.
Clinical features and red flags
Post-molar biochemical disease
A verified hCG plateau or rise during central surveillance is the commonest signal and can establish GTN before symptoms or visible metastases appear.
Post-pregnancy bleeding
Persistent irregular or heavy bleeding after miscarriage, abortion or term birth may indicate choriocarcinoma even without a known preceding mole.
Pulmonary spread
Cough, breathlessness, chest pain or haemoptysis with unexplained hCG requires urgent assessment for lung metastases and haemorrhage.
Neurological spread
Headache, vomiting, seizure or focal deficit can be the presentation of cerebral metastasis and intracranial bleeding in high-risk disease.
Low-hCG tumour phenotype
PSTT and ETT may produce modest hCG despite a uterine mass or metastatic disease, particularly after a long interval from pregnancy.
Red flags requiring action
Heavy or recurrent bleeding after any pregnancy event can arise from vascular intrauterine GTN and may need transfusion, embolisation or emergency surgery coordinated with specialists.
Breathlessness, chest pain, cough or haemoptysis may indicate pulmonary metastases, haemorrhage, embolic disease or another acute diagnosis and requires urgent imaging and escalation.
Severe headache, vomiting, seizure, weakness or altered consciousness suggests possible brain metastasis or intracranial bleeding and needs emergency neuroimaging and multidisciplinary care.
Investigations
01Serial specialist hCGFirst step
Why
Confirm persistent trophoblastic activity, quantify trajectory and monitor response through one consistent assay system.
Interpretation and limitations
A verified plateau or sustained rise meets biochemical concern; compare serum and urine when low-level interference or pituitary hCG is possible.
02Pregnancy assessment
Why
Exclude a new intrauterine or ectopic pregnancy before labelling detectable hCG as neoplasia.
Interpretation and limitations
History, contraception, ultrasound and serial pattern are integrated urgently; a new pregnancy does not explain organ symptoms or known metastatic lesions automatically.
03Chest imaging
Why
Assess the commonest metastatic site and contribute to anatomical stage and risk score.
Interpretation and limitations
Use chest radiography for suspected low-risk disease and CT for high-risk disease or choriocarcinoma; only lung lesions at least 1 cm are counted in the FIGO 2026 risk score.
04Pelvic and abdominal imaging
Why
Define uterine invasion, tumour vascularity and liver, renal or other visceral disease.
Interpretation and limitations
Use pelvic Doppler ultrasound or MRI for low-risk assessment; high-risk disease and choriocarcinoma require contrast-enhanced pelvic MRI and abdominal CT when available. Highly vascular lesions should not be sampled reflexively.
05
Differential diagnosis
01
New pregnancy
A fresh intrauterine or ectopic gestation produces rising hCG and must be assessed with history, serial measurements and ultrasound before cancer treatment.
02
Retained pregnancy tissue
Non-neoplastic products can sustain bleeding and low hCG after miscarriage or abortion, but repeated procedures should follow careful imaging and specialist discussion.
03
Assay interference
Heterophile antibodies may create persistent serum positivity with negative urine, while pituitary hCG can occur at low concentration around menopause.
04
Non-gestational malignancy
Some germ-cell and other tumours produce hCG; genotyping, pathology and clinical context distinguish them from disease derived from a prior pregnancy.
Management
01Abnormal hCGVerify and refer without delayFirst stepPost-pregnancy hCG plateaus, rises or remains unexpectedly detectable on repeated testing.+
1Compile the complete dated hCG series, antecedent pregnancy details, pathology, procedures, contraception and symptoms, and contact the national trophoblastic centre.
2Exclude a new pregnancy and obvious assay problems using centre-directed serum, urine and imaging tests without repeatedly curetting the uterus.
3EscalationAdmit and escalate urgently when bleeding, respiratory, neurological or hepatic symptoms suggest vascular or metastatic complications.
02StagingDefine anatomy and prognostic riskSpecialist assessment confirms or strongly suspects active GTN.+
1Perform centre-directed chest, pelvic and abdominal imaging and brain assessment when indicated, avoiding biopsy of vascular metastatic deposits.
Complications
01
Life-threatening haemorrhage
Vascular uterine or metastatic tumour can bleed into the genital tract, lungs, abdomen or brain and may require embolisation or surgery.
02
Metastatic organ injury
Pulmonary failure, intracranial haemorrhage and hepatic rupture drive early risk in extensive disease and require careful induction and critical support.
03
Treatment toxicity
Cytotoxic therapy can cause mucosal, hepatic, marrow, neurological and reproductive effects that require scheduled testing and rapid symptom reporting.
04
Relapse and surveillance distress
A small relapse risk and repeated hCG testing can sustain anxiety after cure, particularly when conception must be deferred during monitoring.
Monitoring and follow-up
Use the specialist laboratory's hCG schedule during every chemotherapy cycle and after treatment; trend defines response, resistance, consolidation and relapse surveillance.
Check full blood count, renal and liver function and regimen-specific toxicity before treatment intervals, escalating fever, mucositis, bleeding or organ symptoms rapidly.
Maintain direct coordination between the national centre, local oncology service and GP so doses, results and adverse events are not split across unconnected records.
Use effective contraception for the centre-specified period and report any pregnancy immediately because gestational hCG prevents reliable relapse monitoring.
Review fertility, menstrual recovery, psychological wellbeing and cancer-related anxiety, offering specialist reproductive or counselling support according to the patient's priorities.
Special situations
GTN can follow any pregnancy
Choriocarcinoma after term birth or abortion may present with bleeding or metastases, so a remote obstetric history remains diagnostically important.
Do not biopsy the purple lesion
Vaginal or other metastases can be extremely vascular, and apparently simple tissue sampling may produce catastrophic haemorrhage.
Low hCG does not equal low burden
PSTT and ETT secrete less hormone than choriocarcinoma, making imaging, histology and the interval since pregnancy particularly important.
Response is biochemical
Symptoms can improve while active cells remain, so serial hCG and consolidation therapy matter even after the patient feels clinically recovered.
Specialisation preserves cure and fertility
Centralised scoring, chemotherapy and surveillance achieve very high cure rates while avoiding unnecessary operations and excessive multi-agent exposure.
Common pitfalls
01
Calling persistent bleeding retained products after a term pregnancy without checking quantitative hCG.
02
Treating a single low positive hCG as cancer before excluding pregnancy and assay interference.
03
Biopsying a vascular vaginal or metastatic lesion before discussing suspected GTN with specialists.
04
Using local imaging alone to assign risk score without the national centre's staging interpretation.
05
Stopping chemotherapy when hCG first becomes normal instead of completing prescribed consolidation.
06
Assuming hysterectomy alone cures all GTN or that chemotherapy permanently removes future fertility.
JurisdictionUnited Kingdom
Low-risk post-molar disease is commonly treated with specialist methotrexate plus folinic acid, with response measured by serial hCG and therapy continued beyond biochemical normalisation.
High-risk disease requires centre-led multi-agent chemotherapy such as EMA-CO, while ultra-high-risk disease may need lower-intensity induction before full treatment to reduce early catastrophic complications.
Cure rates are excellent with specialist management, but contraception, hCG monitoring, toxicity surveillance, fertility advice and psychological support continue after chemotherapy ends.
Right-upper-quadrant pain, jaundice or haemodynamic collapse can signal hepatic involvement and haemorrhage in high-risk disease.
Persistently detectable hCG after a non-molar pregnancy, especially with bleeding, must not be assumed to be retained products without excluding choriocarcinoma and a new pregnancy.
Brain imaging
Why
Detect cerebral metastases when symptoms, choriocarcinoma, high-risk disease or lung metastases at least 1 cm create concern.
Interpretation and limitations
Contrast-enhanced MRI is preferred; urgent CT is reserved for acute situations when MRI is not immediately available, with haemorrhagic lesions requiring immediate multidisciplinary care.
06Pretreatment safety bloods
Why
Establish marrow, renal and hepatic function before chemotherapy and identify bleeding-related anaemia.
Interpretation and limitations
Abnormal organ function changes drug dosing and supportive care, while severe anaemia or coagulopathy may need correction before intensive treatment.
2Calculate the FIGO 2026 anatomical stage and seven-factor risk score, excluding previous chemotherapy, and identify PSTT, ETT or ultra-high-risk features separately.
3Discuss the plan through the specialist multidisciplinary team, including fertility wishes, haemorrhage control and need for inpatient induction.
03Low riskSelect treatment within the low-risk groupFIGO stage and prognostic scoring place disease in the low-risk group, after checking score 5–6 exceptions and special tumour subtypes.+
1First lineAlternativeFor scores 0–4 and score 5–6 disease without the FIGO 2026 additional risk factors, start the centre's methotrexate and folinic-acid schedule or selected alternative after baseline blood and organ-function assessment; discuss first-line multi-agent treatment when one of those score 5–6 factors applies.
2Measure hCG and toxicity at prescribed intervals, treating mucositis, liver disturbance or other adverse effects and recognising biochemical drug resistance promptly.
3Continue consolidation therapy beyond hCG normalisation for the centre-defined number of cycles, then enter post-treatment surveillance.
04High or ultra-high riskCoordinate multi-agent curative careThe risk score is at least seven, critical metastatic sites are involved or specialist histology changes the treatment model.+
1Admit to or coordinate closely with the national treatment unit and stabilise haemorrhage, organ dysfunction and infection risks before cytotoxic therapy.
2Use EMA-CO or another disease-specific multi-agent regimen, with lower-intensity induction when ultra-high burden makes rapid tumour lysis dangerous.
3Add surgery, embolisation, radiotherapy or central nervous system treatment only through multidisciplinary planning for bleeding, resistant or site-specific disease.
Key medicines and prescribing safety1 treatment · regimens, roles and cautions+
Common UK specialist regimen for low-risk GTN, continued with consolidation after hCG normalisation.
Methotrexate with folinic-acid rescue
In each 14-day cycle, give methotrexate 50 mg intramuscularly at noon on days 1, 3, 5 and 7, with folinic acid 15 mg orally 30 hours after each dose on days 2, 4, 6 and 8; repeat only under the specialist protocol.
Only the trophoblastic centre should initiate and modify treatment; check blood count, renal and liver function and report mucositis, pleuritic pain, ocular symptoms, infection or unexpected bleeding promptly.