Progesterone Test for Fertility

This laboratory test measures the concentration of progesterone in the blood serum. This steroid hormone is primarily secreted by the corpus luteum in the ovary after ovulation in the second half of the menstrual cycle (lunar phase), and by the placenta during pregnancy. It plays a crucial role in preparing and thickening the uterine lining (endometrium) to receive a fertilized egg, and in maintaining the stability of early pregnancy by inhibiting uterine contractions and modulating the immune response.