Human Chorionic Gonadotropin, Serum (HCG)

Nonpregnant state: < 0.01 IU/mL
4 weeks pregnant: 0.10–1.0 IU/mL
16 weeks pregnant: 10–50 IU/mL
. Red-top tube.
■ Hormone produced by the placenta.
■ Levels peak at about 16 weeks and then decline.