La progesterone là một hormone steroid which plays an important role in particular during the installation and development of a mang thai. It is, however, important even outside pregnancy, for the maintenance of the function of the genitals.

It is mainly produced by buồng trứng (apart from pregnancy) and nhau thai (from the second month, taking over from the yellow body). During pregnancy, it allows the migration of the fertilized egg to the uterus, then facilitates its implantation, among other things.

The level of progesterone in the blood varies during the menstrual cycle. It is low during the follicular phase, increases sharply during the luteal phase, reaching a maximum 5 to 10 days after the surge of LH (the luteinizing hormone, which triggers ovulation). The rates then decrease, except in pregnancy.

In the blood, progesterone circulates bound to various proteins (transcortin, albumin and orosomucoid).

The dosage of blood progesterone (progestéronémie) can be done in several situations:

• giữa 20^st Và 23^st day of the menstrual cycle, to ensure that the corpus luteum produces normal amounts of progesterone, necessary for the implantation of a pregnancy (if in doubt during repeated miscarriages)
• during the first weeks of pregnancy, to make sure that it is progressing well (the rate must remain stable)
• to check the effectiveness of ovulation induction in medically assisted procreation
• to diagnose an ectopic pregnancy (in combination with the hCG test), the progesterone then being abnormally low
• in the case of medically assisted procreation, for in vitro fertilization and embryo transfer, or to program intrauterine inseminations (it is a marker of ovulation)

The blood test is carried out on a venous sample, generally at the bend of the elbow. No preparation is required, but the date of the last period or the start of pregnancy must be specified.

As a guide, normal blood levels of progesterone outside pregnancy are less than 1,5 ng / mL during the follicular phase, between 0,7 and 4 ng / mL at the time of peak ovulation and between 2 and 30 ng / mL during the luteal phase (reflection of the presence of the corpus luteum).

They decrease at the thời kỳ mãn kinh.

During pregnancy, at the 5st tuần củamất kinh, they are about 40 ng / mL and reach 200 ng / mL at the end of mang thai.

When abnormally low levels of progesterone are detected, especially in a woman who wishes to become pregnant, supplementation may be considered in the second part of the cycle.

Cuối cùng, lưu ý rằng progestéronémie may be increased in several pathologies, in particular certain ovarian or adrenal tumors or certain congenital deficits.

Only the doctor will be able to interpret the results and make a diagnosis, sometimes with the help of additional tests or analyzes.