Pre-test preparation or requirements
• Sample can be drawn at any time. No fasting or special preparation required.
• Sample should taken in plain vial.
Approximate Gestational Age (weeks) Reference Value
1-10 50-221796 mIU/ml
11-15 15205-227034 mIU/ml
16-24 5002-75445 mIU/ml
25-40 1501-69208 mIU/ml
Significance of test
HCG is produced in the placenta during pregnancy. In non-pregnant women, it can also be produced by tumors of the trophoblast, germ cell tumors with trophoblastic components and some non-trophoblastic tumors. The serum of pregnant women contains mainly intact HCG. HCG molecule appears between 2 to 8 days after fertilization in the embryo's culture medium. HCG can be detected in maternal serum 7 days after fertilization and 8 days following ovulation. HCG increases 3-fold between the day of detection and the next day, decreasing thereafter and reaching 1.6 fold between Days 6 and 7. The HCG concentration increases exponentially in the first trimester, doubling every 31-48 hrs and reaches greater amounts between 11 and 13 weeks. In the second trimester, at 20 weeks gestation, it diminishes to 80% and remains in this concentration until the term. The HCG is more negatively charged in the early than in the latter stage of gestation and this change in charge occurs around week 13, when the placental production of estradiol and progesterone increases. Unusually low or rapidly declining levels may indicate an abnormal condition such as an ectopic pregnancy or impending spontaneous abortion.