What type of medication is progesterone in the context of pregnancy?

Progesterone is classified as a hormone that plays a crucial role in maintaining the uterine lining during pregnancy. After ovulation, progesterone levels rise and prepare the endometrium (the lining of the uterus) for potential implantation of a fertilized egg. This hormone is essential for establishing and maintaining a pregnancy, as it helps to create a supportive environment in the uterus and prevents contractions that could lead to early labor. In addition to its role in the menstrual cycle, progesterone also contributes to the physiological adaptations necessary for pregnancy, making it vital for both the health of the mother and the development of the fetus.