Human chorionic gonadotropin (hCG) is a hormone produced during pregnancy. hCG levels rise rapidly in early pregnancy and can indicate multiple pregnancies, Down syndrome, or an ectopic pregnancy if levels are low. Serial hCG measurements are used to monitor pregnancies of unknown location, diagnose failing pregnancies, and guide treatment for gestational trophoblastic diseases like molar pregnancies. Discriminatory hCG levels, doubling times, and international criteria help determine management for these conditions.

1. INTERPRETATION OF hCG LEVELS?

6. Return of hCG NVD 3 wks Abortions 6 wks Molar pregnancy 8-9 wks

8. Positive urinary hCG TVS Pregnancy of Unknown location Serial serum hCG and progesterone Initial progesterone <20nmol/L serial hCG <66% or plateauing hCG Initial hCG >=1500IU/L hCG<500IU/L Plateauing, negative TVS & laparoscopy ↑ serial hCG >= 66% Probable failing PUL Probable IUP Possible EP Probable EP ? Persisting PUL Repeat serum hCG in 1 week Rescan in 2 weeks Close monitoring with seial hCG/TVS until diagnosis made or hCG<15IU/L Laparoscopy Methotrexate

11. TVS IUP No IUS Adenexal mass -EP No adenexal mass or sac Rept hCG after 48 hrs < 66% rise > 66% rise IUP TVS Failing pregnancy D&C

14. FIGO score 0 1 2 4 Age (years) <39 >39 Antecedent pregnancy Hydatidiform mole Abortion Term pregnancy Interval from index pregnancy (months) <4 4-6 6-12 >12 Pretreatment hCG (mIU/mL) <1000 1000-10,000 10,000-100,000 >100,000 Largest tumor size including uterus (cm) 3-4 5 Site of metastases Spleen Kidney Gastrointestinal Brain lever Number of metastases identified 0 1-4 4-8 >8 Previous failed chemotherapy Single drug >2 drugs

15. Category Criteria Non-metastatic GTN No evidence of metastases; not assigned to prognostic category Metastatic GTN Any extrauterine metastases Good prognosis metastatic GTN No risk factors: Short duration (<4 months) Pretherapy hCG < 40,000 mIU/ mL Pretherapy hCG <40,000 mIU/ mL No brain or liver metastases No antecedent term pregnancy No prior chemotherapy Poor prognosis Metastatic GTN Any one risk factor: Long duration (>4 months) Pretherapy hCG > 40,000 mIU/ mL Brain or liver metastases Antecedent term pregnancy Prior chemotherapy