What is the function of the human chorionic gonadotropin (hCG) injection?

Its primary clinical use is to support pregnancy maintenance. Following conception, the concentration of human chorionic gonadotropin (hCG) in the bloodstream rises rapidly. hCG is a glycoprotein hormone secreted by the placental trophoblast cells and serves as a highly reliable indicator of early fetal development within the uterus.

Suboptimal or inadequate hCG doubling—i.e., failure of hCG levels to double appropriately over the expected timeframe—suggests compromised fetal development and increases the risk of threatened miscarriage. Therefore, pregnant women exhibiting such patterns often require exogenous hCG administration.

Additionally, many of these women concurrently present with low progesterone levels and typically also require supplemental progesterone (e.g., intramuscular or vaginal micronized progesterone). A favorable therapeutic response—characterized by appropriate hCG doubling, rising hCG levels, and ultrasound confirmation of fetal development including detection of fetal cardiac activity—indicates successful pregnancy support.