WHAT IS PREGNANCY TEST (HCG) ROUTINE (SERUM AND QUALITATIVE) TEST?
Human chorionic gonadotropin (hCG) is a hormone uniquely secreted by the placenta of a fertilized ovum implanted in the uterine wall. hCG production begins 8-10 days after conception or during days 21-23 of the cycle. It reaches peak concentration at 8-12 weeks of gestation and then gradually decreases until returning to normal within 3-4 days after normal full-term delivery. This test can be most accurately performed from 2 days to 3 weeks after missed menses.
Serum testing is performed by incubation of serum with anti-human chorionic gonadotropin (anti-hCG). If hCG is present in the sample, it combines with the anti-hCG antibodies and inactivates them. When these inactivated antibodies are exposed to the indicator, which is red or latex cells coated with hCG, clumping of the cells does not occur, resulting in a positive pregnancy test. If clumping does occur, the test is negative.