Beta-HCG Level, β-HCG, Human chorionic gonadotropin (HCG) Sample. This test is done on the serum or urine of the patient. Can save serum at 2 to 8 °C for 24 hours for total HCG. For more time keep serum at -20 °C. This is a blood test to detect beta-HCG . Human chorionic gonadotropin (hCG) conversion to mIU/mL, IU/L. Online conversion calculator for many types of measurement units in laboratory and medicine Human chorionic gonadotropin (hCG) , Human chorionic gonadotropin (hCG) conversion to mIU/mL, IU/L. Online converter from conventional units to SI units | UNITSLAB.COM. The most sensitive, accurate and reliable pregnancy test is a blood test for the presence of beta HCG (human chorionic gonadotropin), often just called beta. The HCG is produced by the embryo, and is the embryo's signal to the mother that pregnancy has occurred. Beta HCG levels vary according to the gestational age.. hCG is made up of alpha and beta subunits. The beta subunit is specific for hCG. Immunologic tests are performed by using commercially prepared antibodies against the hCG and its subunits (particularly the beta subunit). Most of these laboratory methods use sandwich type immunoassay.. "HCG is detectable in the blood serum of approximately 5% of pregnant women by 8 days after conception, and in virtually all the rest by 11 days. HCG rises progressively from conception. Levels double on the average, every 30.9 hours until values reach 6500 mIU/ml (6,500 IU/L) at approximately the eighth week after the last menstrual period (LMP).. free-beta hcg and papp-a (iu/l) results: hi I am need of some help to understand my results as I am not to sure what they mean or if its something bad. my free-beta hcg result was 36.3 and papp-a(iu/l) results were 0.329 does anyone know what that means? - BabyCenter Australia.