Human chorionic gonadotropin (hCG) is a hormone produced during pregnancy. It is secreted by the placenta shortly after a fertilized egg attaches to the uterine lining. hCG plays a crucial role in maintaining the pregnancy by supporting the production of other hormones, such as progesterone, which is essential for a healthy gestation. hCG is commonly used in medical settings for various purposes, including pregnancy tests, which detect its presence in urine or blood. Additionally, it is sometimes used in fertility treatments to stimulate ovulation and support reproductive health in both women and men.