hCG is human chorionic gonadotropin
. This glycoprotein hormone
is produced when the fertilized egg
implants into the uterine lining (the placenta
) during pregnancy
. Home pregnancy tests are designed to detect this hormone. The home pregnancy tests that detect the lowest number of mIU
give the earliest results.
hCG is composed of two subunits. The alpha subunit is common to all glycoprotein
hormones in a given species. while the beta subunit is hormone specific.