AUBF PREGNANCY TESTING

Human Chorionic Gonadotropin (HCG)

• Glycoprotein hormone secreted by the trophoblast of the developing embryo that rapidly increases in urine or serum during the early stages of pregnancy

Human Chorionic Gonadotropin (HCG)

Uses:

• pregnancy testing

• gestational trophoblastic disease (hydatidiform mole)

• testicular tumor, other HCG producing tumor

Alpha Subunit

similar to LH, FSH and TSH

Beta Subunit

unique to HCG

First 6-8 weeks of conception

B-HCG helps maintain the corpus luteum and stimulate the production of progesterone

2-3 days (48 - 72 hrs.) after implantation, or 8-10 days after conception

Secretion of detectable amounts of b-hCG (25 mIU/mL)

2-3 months after last menstrual period

peak levels are reached

10-16 weeks

b-hCG decreases, plateaus and remain constant until pregnancy is in full term

Serial monitoring of hCG

- Used to ensure development of healthy pregnancy

- Monitor complete expulsion of pregnancy after termination

Termination of Pregnancy/ Delivery

7-60 days to return to non-pregnant levels

Ectopic Pregnancy

1-31 days (Median of 8.5) for hCG to disappear

Fetal Down Syndrome

hCG 2x higher in maternal serum (pregnancy abnormalities)

Trophoblastic tumor

hCG continue to rise after 10 weeks:

non-viable

hCG plateau before 8 weeks or fail to double in conc. every 24hrs

ASCHEIM-ZONDEK

• Immature female mice

• Mode of Injection: Subcutaneous

• (+) formation of hemorrhagic follicles and corpora lutea

FRIEDMAN

• Mature virgin female rabbit

• Mode of Injection: Marginal ear vein

• (+) hyperemic uterus and corpora hemorrhagica

HOGBEN

• Female toad

• (Xenopus laevis)South African clawed frog: carries egg throughout the year

• Mode of Injection: Lymph sac

• (+) oogenesis and ovulation

GALLI - MAININI

• Male frog (Rana pipiens or Rana clamitans, leopard or grass frog)

• Male toad (Bufo bufo or B. americanus)

• Mode of Injection: Subcutaneous

• (+) spermatogenesis

FRANK - BERMAN

• Immature female rats

• Mode of Injection: Subcutaneous

• (+) ovarian hyperemia

KUPPERMAN

• Female rat

• Mode of Injection: Intraperitoneal

• (+) ovarian hyperemia

1. Complement fixation

2. Hemagglutination-inhibition

3. Latex particle agglutination inhibition

4. Direct agglutination

5. Enzyme immunoassay

Immunoassays

Enzyme Immunoassay

What is the principle of homebased pregnancy test kit?

• Anti-hCG is impregnated on a membrane strip

• (+) hCG: Chromatographic reaction occurs

Home-based Pregnancy Test Kit

First morning urine

What is the specimen for homebased pregnancy testing?

atleast 1.015

Specific gravity of P.T.

25 mIU/mL

Cut off point for PT

Rabbit

what is the source of Anti-hCG

Increased Protein

False positive

Hydatidiform Mole

False positive

False positive

Testicular tumors

Chorioepithelioma

False positive

Excessive ingestion of aspirin

false positive

Dilute urine

False negative

Undetectable levels of hCG

False negative