EQ penis Medically reviewed by the Healthline Medical Network. Testis Medically reviewed by the Healthline Medical Network. HCG is a hormone that plays an important role in pregnancy. But high or low levels of hCG can indicate certain health Equipoise in anyone. In this article, we look at hCG in detail including normal ranges during pregnancy, what happens when levels fluctuate, and how doctors use the measurements to identify underlying health conditions.