Transcript HCG

PBL
HOMEWORK of OB/GYN
on Human Chorionic
Gonadotropin (HCG)
87KE4 team3
Preview
I.
II.
III.
IV.
What is HCG?
How to test HCG?
What is the clinical significance of
HCG detection?
Home pregnancy tests (HPTs)
I.
 1.hCG
HCG
is glycoprotein hormone
produced by normal trophoblast
cells(合体滋养细胞） of the placenta
during pregnancy.
 2.hCG
production starts just a few
days after conception（受孕）, before
implantation in the uterus.
 hCG enters the maternal circulation
almost immediately after
implantation， about day 21 of the
menstrual cycle.
 3.hCG
is composed of two subunits,
alpha and beta
 4.The
alpha-subunit is identical to
that of the pituitary glycoprotein
hormones:
 lutenizing hormone (hLH),
 follicle stimulating hormone (hFSH)
 thyroid stimulating hormone (hTSH).
 5.The
ß-subunits of the glycoprotein
hormones are unique, giving them
their different biological
characteristics.
 6.physical
function:
 1) 作用于月经黄体，增加甾体激素的分泌，
以维持妊娠
 ２）有促卵泡成熟活性，促甲状腺活性，
促睾丸间质活性
 ３）与尿促性素合用能诱发排卵
 ４）激素屏障：抑制淋巴细胞活性
Ⅱ.How to test HCG?
qualitative urine or blood hCG
test is ordered as early as 10 days
after a missed menstrual period if a
woman wishes to confirm whether or
not she is pregnant
 １.A
2.Affecting factors
 1)Tests performed too early
 2) a false negative result in very dilute
urine. Patients should not drink large
amounts of fluid before collecting a urine
sample for a pregnancy test.
 3)drugs: （1）diuretics and promethazine
(异丙嗪) false-negative urine results. （2）
anti-convulsants, anti-parkinson drugs,
hypnotics, and tranquilizers false-positive
results.

test: hCG kits can detect a
wide and varying range of different
hCG-related molecules in serum or
urine samples.
 ３.Special
The molecules detected include
5 groups:
 1).non-nicked
hCG (完整的HCG) the
active hormone
 2).nicked hCG （缺口hCG）
 3).hyperglycosylated
HCG(高糖基化
HCG)最新研究表明如果此型HCG在妊娠七
周时维持在较高水平不下降则预示妊娠异
常
 4).asialo hCG (缺乏唾液酸基的HCG),
 5) hCG-CTP or free ß-subunit can
ⅢWhat is the clinical
significance?
 1.
Normal pregnancy
 FIGURE
 The
"normal" ranges for the HCG in
blood pregnancy test

1) The concentration of may reach up to
150,000 mIU/ml in both serum and urine.
 2)hCG levels rise exponentially for the first
8 weeks of pregnancy,
 3) reaching a peak at 10 weeks after the
last menstrual period.
 4)In the following 10 weeks levels slowly
decline to approximately one fifth of peak
levels and remain around one fifth of peak
levels until term
 2.
Early pregnancy loss (EPL)
This is an embryo which fails to
implant properly in the uterus, or is
rejected by the uterus. It is followed
by a normal or slightly heavier than
normal menstrual period.

hCG concentration reaches a peak
after 2 weeks conception (28 days
after start of last menstrual period)
at 10 to 100 mIU/ml, then rapidly
declines. Normal or slightly heavier
than normal menses follow.
 3.
Ectopic or extrauterine
pregnancy
In women with extrauterine or
ectopic pregnancies, unduly low hCG
levels may be detected.
 最新研究表明如果腹腔血beta-HCG定性检
查为阳性者100%为异位妊娠
4
Gestational Down syndrome
 5 Hydatidiform mole hCG
concentration may be as high as
2,000,000 mIU/ml.
 6 Persistent trophoblast
disease or persistent mole
7
Choriocarcinoma
 8. Germ cell, bladder and other
non-trophoblastic malignancies
 9. pituitary hCG production
 10. false positive hCG production
Ⅳ HPT( Home pregnancy tests)
 use
midstream urine
 you need to hold the absorbant
tip of the stick in the cup of urine
for 5-10 seconds
 In the result window, the tests
usually give a line or a plus.
 Examples of line tests.doc