interpretation of hcg
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INTERPRETATION OF hCG LEVELS?
Glycoprotein with α and β chains β subunit is specific to hCG Secreted by trophoblastic tissue, some amount by
fetal tissues, adult ant pituitary Many isoforms of hCG with variable crossreactivity
between various assays More than 100 commercial assays Sandwich type immunoassay: Sens - 1mIU/ml Immuno radiometric assays: more Sensitive
1. Pregnancy
2. Gestational trophoblastic neoplasia
3. Non gestational Trophpoblastic neoplasiaMixed germ cell tumors
Always rule out pregnancy whenever hCG is positive.
It does not localize the pregnancy USG to lacalise the pregnancy
Significantly higher levelsMultiple pregnancyErythroblastosis fetalisDown’s syndrome
Low levels : ectopic pregnancy, abortions
+ve 7-9 days after the midcycle surge that precedes ovulation.(time of blastocyst implantation)
Blood levels rise rapidly, double every 1.4 - 2 days, max value at 8-10 wks.
Peak values: 60-80 days of LMP(1 lac mIU/ml)
10-20 wks POG: begin to fall, nadir levels by 20 wks & maintained at lower levels thru out pregnancy
Return of hCG
NVD 3 wks
Abortions6 wks
Molar pregnancy8-9 wks
Discriminatory level Lower limit above which one can reliably
visualisepregnancy
1500 mIU/ml for TVS
Doubling timeIUP : serum hCG levels ↑ 66% every 48 hrsInappropirately rising serum hCG→ dying
pregnacy & not its location
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/LPlateauing, 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
Mrs. X, 28 yrs G 5 P0+0+4+0
C/O Amenorrhoea - 49 daysPain Abd - 1 day
O/E Haemodynamically stableP/S Uterus soft, bulky, fx free,
No cervical excitationUPT PositiveTVS ET - 13.4mm
No IU sacNo adenexal mass/fluid in
POD
Serum βhCG – 300 IU/L
Failing PUL IUP EP
Rept. Serum βhCG after 48 hrs : 877 IU/L
(Rise > double)
Rescan after 48 hrs
IUP
TVSIUP No IUS
Adenexal mass -EP
No adenexal mass or sac
Rept hCG after 48 hrs
< 66% rise> 66% riseIUPTVS
Failing pregnancy
D&C
Medical treatment Pre T/t level: 5000 mIU/ml – 92% success Follow up: D1 -- baseline
D4 -- level >D1
D7 -- 15% fall from D4 Every week till 15 IU/L
20% will have decline of hCG < 15% : second dose of Methotrexate
Average duration for hCG level to reach normal - 36 days Longest duration - 109 days
Expectant treatment < 1000 mIU/ml < 200 IU/L ----- spontaneous resolution in 88-96 %
High risk molar: > one lac mIU/ml
Follow up : within 48 hrs of evacuationevery wk till hCG is normal x 3
wks every month x 6 months
FIGO criteria for chemo
Plateauing (+ 10% value ,4 values over 3 wks)
Rising hCG (increase of > 10% of 3 values recorde
over a 2 week duration)
Persistent hCG after 6 months of evacuation
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
Category Criteria
Non-metastatic GTN No evidence of metastases; not assigned to prognostic category
Metastatic GTN Any extrauterine metastases
Good prognosismetastatic GTN
No risk factors:Short duration (<4 months)
Pretherapy hCG< 40,000 mIU/ mL
Pretherapy hCG <40,000 mIU/ mLNo brain or liver metastasesNo antecedent term pregnancyNo prior chemotherapy
Poor prognosisMetastatic GTN
Any one risk factor:Long duration (>4 months)Pretherapy hCG > 40,000 mIU/ mLBrain or liver metastasesAntecedent term pregnancyPrior chemotherapy
Surveillance During And After Therapy of GTN
Monitor serum quantitative hCG levels every week during chemotherapy:
1.Response: > 10% decline in hCG during one cycle2.Plateau: + 10% change in hCG during one cycle3.Resistance: > 10% rise in hCG during one cycle or plateau for two Remission: 3 consecutive normal weekly hCG values
Surveillance of remission:1.hCG values every 2 weeks X 3 months2.hCG values every month to complete one year of follow-up3.hCG values every 6-12 months indefinitely; at least 3-5 years
75 -110 mIU/L ( max reported 300 mIU/L)
After chemo/ surgery of GTN No clinical/radiological evidence of
trophoblastic tissue
phantom hCG Quiscent GTN (false +ve) (real +ve)
(Benign or inactive)
75 -110 mIU/L ( max reported 300 mIU/L)
After chemo/ surgery of GTN No clinical/radiological evidence of
trophoblastic tissue
phantom hCG Quiscent GTN (false +ve) (real +ve)
(Benign or inactive)
Phantom hCG
Heterophilic abs
React with animal Ag in immuno sandwich assay
Confirm by
Urine hCG –ve
different assays
no change in dilutions
other techniques to srip/
block/ inactivate abs
Quiscent GTN
Most often after molar, GTN, pregnancy
Do not respond to chemo Diagnosis
Hyperglycosylated hCG < 6%(hCG – H)
Serial hCG titres: plateau 5,10,20,22,8,25,24
Withhold chemo Premalignant (1-11%) Monthly FU, glycosylated
hCG, Slow growing
syncytiotrophoblast