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  • Gestagens

    Gestagens( progestational steroids) are produced in the ovaries, testicles, in the adrenal cortex, and during pregnancy - in the placenta. The action of gestagens is aimed at the realization of the normal reproductive function of the body. The main representative of this group of hormones is progesterone.

    Progesterone in the blood serum

    Progesterone promotes the proliferation of the uterine mucosa, facilitates the implantation of a fertilized egg. Progesterone is synthesized by a yellow body, and during pregnancy, the placenta becomes its main source. Measurement of the concentration of progesterone in the blood is performed to confirm or exclude ovulation during the menstrual cycle. Reference values ​​of progesterone concentration in blood serum are presented in the table.

    Table Reference values ​​of progesterone concentration in blood serum

    Table Reference values ​​of progesterone concentration in serum


    The main target organ of progesterone is the uterus. The hormone causes a secretory transformation of proliferatively thickened endometrium, thereby ensuring its readiness for implantation of a fertilized egg. Moreover, progesterone carries an important control function in the gonadotropin-gonadal steroids system and causes stimulation of the heat center. This causes an increase in body temperature by 0.5 ° C in the luteal phase of the menstrual cycle after ovulation.


    Day of the menstrual cycle

    Fig. Change in serum progesterone concentration during the normal menstrual cycle

    Day of the menstrual cycle

    Fig. Change in serum progesterone concentration during the normal menstrual cycle

    Changes in progesterone concentration during the normal menstrual cycle are shown in Fig. Until the end of the LH peak, the concentration of progesterone remains extremely low. Nevertheless, simultaneously with the peak of LH in the middle of the cycle, there is a small but significant increase in the concentration of progesterone, followed by a decrease. In parallel with estradiol, the level of progesterone begins to rise again in the second half of the cycle. This means that the luteinization is completed. By the end of the cycle, the concentration of progesterone again falls and reaches the values ​​of the first, follicular phase, in which the effect of the yellow body is practically absent. This sharp drop in the concentration of progesterone causes menstrual bleeding.

    The main diseases and conditions in which the serum progesterone concentration can vary are shown in the table.

    Table Diseases and conditions in which serum progesterone concentration changes

    Table Diseases and conditions in which serum progesterone concentration changes