on Human Chorionic Gonadotropin (HCG) PBL HOMEWORK of OB/GYN on Human Chorionic Gonadotropin (HCG) 87KE4 team3

Preview What is HCG? How to test HCG? What is the clinical significance of HCG detection? Home pregnancy tests (HPTs)

HCG 1.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? １.A 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

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.

３.Special test: hCG kits can detect a wide and varying range of different hCG-related molecules in serum or urine samples.

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