What is progesterone? Is progesterone the same as progesterone?

In the early stages of pregnancy, pregnant mothers will check their progesterone levels during prenatal checkups. However, many pregnant mothers do not know what progesterone is, let alone what the size of the progesterone level means. Today, the editor will give you some scientific knowledge~

What is progesterone

Progesterone, also known as progesterone, abbreviated as "P", is also called progesterone, progesterone, progestin, progestin, progestin or progesterone. It is a steroid involved in the female menstrual cycle, pregnancy and the embryos of humans and other animals. It is produced by the corpus luteum of the ovary in early pregnancy. During pregnancy, progesterone is an important hormone that supports the early growth and development of the fetus. High concentrations of progesterone have a significant calming effect on the enlarged uterus and are also very important for supporting early pregnancy.

During pregnancy, hCG stimulates the corpus luteum to produce progesterone; from 7 to 9 weeks, the placenta gradually forms, also known as corpus luteum placenta transfer; from 10 to 11 weeks, the placenta produces significantly more progesterone, at which time the trophoblast of the placenta takes over the corpus luteum to produce progesterone and maintain pregnancy. Progesterone testing is mainly used to understand the function of the corpus luteum, whether the ovaries have ovulated, and the status of pregnancy.

The role of progesterone in early pregnancy

1. Progesterone inhibits uterine contractions

Some people believe that progesterone can change the permeability of the uterine muscle cell membrane to ions, making the membrane in a hyperpolarized state, thereby reducing the excitability of the uterine muscle and also reducing the sensitivity of the uterine muscle to various stimuli (especially oxytocin). Therefore, the pregnant uterus will not undergo violent and progressive contractions, the embryo will not be affected, and the pregnancy can be maintained. Based on this, progesterone is often used clinically to maintain pregnancy.

Some people hold the opposite view, believing that although the experiment proves that progesterone inhibits the excitement of uterine muscles, it is an in vitro condition and the dose used in the experiment far exceeds the physiological concentration. In addition, when treating threatened abortion, the double-blind method was used and it was found that the effect of progesterone and placebo was equivalent.

2. Progesterone maintains the membrane removal reaction

Decidual cells are transformed from endometrial stromal cells and contain glycogen granules, which provide nutrition for the blastocyst. Injecting "rabbit anti-mouse decidual serum" into pregnant mice can cause abortion, which shows the importance of decidualization in maintaining pregnancy. Removal of both ovaries of animals with pseudopregnant decidual reaction can cause decidual necrosis and liquefaction; if exogenous progesterone is given, decidual degeneration can be prevented. It can be seen that progesterone is necessary to maintain the decidual reaction.

3. Progesterone suppresses immune response

The fertilized egg is a "semi-allogeneic transplant", but why is it not rejected by the mother's immune system when implanted? Some people have found that when certain tumor cells are transplanted into the uterine cavity of animals, only in animals injected with progesterone will the tumor cells not be rejected and implanted into the uterine wall, indicating that progesterone can inhibit immune response. The same reason can explain that during normal pregnancy, the increase of progesterone can prevent the embryo from being rejected by the mother and maintain pregnancy. If progesterone is insufficient, the embryo is like a foreign body and is rejected by the mother, resulting in miscarriage.

In short, progesterone is necessary to maintain pregnancy, so it is called "progestational" hormone. No matter what its mechanism of maintaining pregnancy is, it must always bind to the receptors of its target tissue, the endometrial cells, to produce an effect. The synthesis of progesterone receptors is mainly promoted by estrogen. Therefore, the effect of progesterone always depends on the cooperation of estrogen; and estrogen can also stimulate the ovarian corpus luteum to synthesize and secrete progesterone.

How to check progesterone

The progesterone test is done by drawing blood from the pregnant mother's vein. Since the progesterone content is not affected by food, the test does not require fasting, and water can be drunk during the test. Generally, after the test in the morning, the results can be obtained in the afternoon.

Progesterone test precautions

In the entire menstrual cycle of a normal non-pregnant woman, the progesterone level is lowest before ovulation, starts to rise after ovulation, and is highest during the luteal phase. Before ovulation, the progesterone level in body fluids should be lower than 2 ng/ml, and after ovulation it should be higher than 5 ng/ml. If pregnant, the progesterone level will initially remain at the luteal phase level, and when the placenta is formed, the hormones secreted by the placenta will increase the progesterone level in the pregnant woman's body to 100-200 ng/ml, which is dozens to hundreds of times higher than that of non-pregnant women.

Normal progesterone levels

We all know that a quantitative level of progesterone hormone is a necessary condition for maintaining pregnancy. High concentrations of progesterone have a significant calming effect on the enlarged uterus, which is very important for supporting early pregnancy. Progesterone can relax uterine muscle fibers and reduce excitability. At the same time, it reduces the sensitivity of the pregnant uterus to oxytocin, reduces uterine contractions, and is conducive to the growth and development of the fertilized egg in the uterus. If the progesterone level is insufficient, it will lead to threatened abortion or miscarriage. So what is the normal value of progesterone? The following is a reference data of progesterone for women at different stages.

Normal values ​​of progesterone at different stages:

Measurement time Specimen Old system unit Normal value Old-new coefficient Legal unit Normal value New-old coefficient

Follicular phase blood 0.2～0.6ng/ml 3.18 0.6～1.9nmol/L 0.3145

Luteal phase blood 6.5～32.2ng/ml 3.18 20.7～102.4nmol/L 0.3145

7 weeks of pregnancy blood 24.5±7.6ng/ml 3.12 76.4±23.7nmol/L 0.32

8 weeks of pregnancy blood 28.6±7.9ng/ml 3.12 76.4±23.7nmol/L 0.32

Follicular phase blood 24.5±7.6ng/ml 3.12 89.2±24.6nmol/L 0.32

9-12 weeks of pregnancy 38.0±13.0ng/ml 3.12 118.6±40.6nmol/L 0.32

13-16 weeks of pregnancy 45.5±14.0ng/ml 3.12 142.0±43.7nmol/L 0.32

17-20 weeks of pregnancy 63.3±14.0ng/ml 3.12 197.5±43.7nmol/L 0.32

21-24 weeks of pregnancy 110.9±35.7ng/ml 3.12 346.0±111.4nmol/L 0.32

25-34 weeks of pregnancy 165.3±35.7ng/ml 3.12 514.8±111.4nmol/L 0.32

35 weeks of pregnancy blood 202.0±47.0ng/ml 3.12 630.2±146.6nmol/L 0.32

Menopausal blood <1.0ng/ml 3.18 <3.2nmol/L 0.3145

13-36 weeks of pregnancy 55ng/ml 3.12 171.6nmol/L 0.32

Full-term pregnancy blood 26ng/ml 3.12 81.1nmol/L 0.32

Note: Different hospitals use different units for conversion. If the reference value on the test report you received is in ng/ml, for example, the normal value of the old system unit for the follicular phase X 3.18 is converted to the unit of nmol/L; the normal value of the legal system unit for the follicular phase X 0.3145, the old system unit of ng/ml can be obtained by conversion.