Progesterone

The active ingredient progesterone is a sex hormone naturally occurring in the body from the group of gestagens. Progesterone is almost exclusively produced in the corpus luteum. Although progesterone is considered the female sex hormone, it is produced in both women and men. In men, progesterone is produced as an intermediate product of testosterone synthesis in the tests. Furthermore, in both sexes progesterone is produced in the adrenal gland.

Highest serum levels are found in the middle luteal phase (day 5-8 after ovulation). During pregnancy the hormone is produced by the corpus luteum and the placenta. At the end of the pregnancy the progesterone level is increased up to 10 times. The hormone is metabolised in the liver by cytochrome P450 enzymes,

As a drug, the active ingredient is usually administered in cases of a deficiency of natural hormone.

The production of progesterone is regulated by hormone releases from the hypothalamus and pituitary gland. The gonadotropin-releasing hormone (GnRH) is released into the pituitary gland through the hypothalamus. In the anterior lobe of the pituitary, the GnRH then stimulates the secretion of luteinizing hormone (LH), which stimulates progesterone synthesis.

This mechanism is based on the stimulation of cholesterol monooxygenase, an enzyme that catalyses the first step in progesterone synthesis, the conversion to pregnenolone. In a second step Pregnenolone is synthesized to Progesterone. This step is catalyzed by the 3β-hydroxysteroid dehydrogenase. An increasing concentration of progesterone in the blood plasma inhibits the secretion of GnRH by the hypothalamus and consequently the synthesis of hormones. This mechanism is known as negative feedback.

Determination method: ECLIA, LIA; reference ranges (ng/ml):

• foil phase: 0.2-1.5
• Early luteal phase: >5
• Middle luteal phase: >12
• Postmenopausal phase: 0.1-0.8
• Pregnancy:
  • first trimester: 13 - 44
  • second trimester: 44-175
• Men: 0,2-1,4

Increase values:

• Ovarian tumors (thecacell tumor; chorionepithelioma s. tumor marker)
• Bladder mole, congenital or acquired forms of AGS, -pregnancy; induced hyperstimulation

Decreased values:

• Ovulation disorders (corpus luteum insufficiency, anovulatory cycle)
• Primary or secondary hypogonadism, immediately postpartum
• anorexia nervosa
• menopausal

• potentially decreased: polycystic ovarian syndrome (PCOS)

  
  

• a comprehensive assessment of a progesterone level is only possible in the context of the other hormone status
• for clarification of the luteal function the repeated determination of progesterone in the second cycle phase is useful
• Progesterone is released intermittently from the corpus luteum depending on the episodic LH secretion. This results in considerable serum fluctuations for progesterone.

1. Böhm C et al (2017) in: Neumeister B et al. clinical guide to laboratory diagnostics. Urban&Fischer Publisher Munich S. 342