2. Modified WHO Prognostic Scoring System as adapted by FIGO for GTN.
| Scores | 0 | 1 | 2 | 4 |
| Age (years) | < 40 | ≥ 40 | – | – |
| Antecedent pregnancy | mole | abortion | term | – |
| Interval months from index pregnancy | < 4 | 4–6 | 7–12 | > 12 |
| Pretreatment serum hCG (IU/L) | < 103 | 103 to 104 | 104 to 105 | > 105 |
| Largest tumour size (including uterus) | < 3 | 3cm to 4 cm | ≥ 5 cm | – |
| Site of metastases | lung | spleen, kidney | gastrointestinal | liver, brain |
| Number of metastases | – | 1to 4 | 5 to 8 | > 8 |
| Previous failed chemotherapy | – | – | single drug | ≥ 2 drugs |
| To stage and allot a risk factor score, a patient's diagnosis is allocated to a stage as represented by a Roman numeral I, II, III, and IV. This is then separated by a colon from the sum of all the actual risk factor scores expressed in Arabic numerals, i.e., stage II:4, stage IV:9. This stage and score will be allotted for each patient.(FIGO 2009). A score ≤ 6 indicates low‐risk; > 6 indicates high‐risk. | ||||
hCG = human chorionic gonadotrophin; IU = Internationa Units