Coretests, Inc.

Human chorionic gonadotropin---or HCG---is frequently called the "pregnancy hormone". Most trying-to-conceive women who have taken more than a few pregnancy tests already know that hCG is the hormone that is detectable by pregnancy test kits (or by hCG blood tests in your doctor's office). However, typically only doctors know the details behind hCG and its function as a reproductive hormone.

hCG is secreted by the placenta shortly following implantation of the egg. To summarize, shortly after ovulation takes place, the egg is fertilized (conception) and a few days later the fertilized egg (now called an embryo) implants in the wall of the uterus. At this point, the hCG hormone starts flowing---produced by the "pregnancy cells" and incipient placental tissues. hCG will pass into a woman's system and will be present in both blood and urine samples.

What is HCG?