Progesterone is a very important progesterone for women, which regulates the endocrine system and maintains the stability of the internal environment. If a woman has low progesterone during pregnancy, it can have a great impact on the fetus. For example, it can cause a series of effects such as the failure of fertilized egg to properly implant, poor fetal development, embryonic arrest, pre-eclampsia miscarriage, and miscarriage in large months. The main role of progesterone is to maintain the balance of progesterone in a woman’s body so that the fetus can grow safely in the womb, and also to prepare for lactation together with estrogen. If a pregnant woman’s progesterone is too low, it is likely to cause poor fetal growth and development, which can affect fetal abortion and miscarriage in the long term. Especially for those pregnant women with a history of pre-eclampsia and multiple spontaneous abortions, it is important to monitor progesterone and give progesterone supplements if necessary. But is progesterone supplementation necessary for all pregnant women who do not have an indication for medication? No. Both high and low progesterone are not good. Excessive progesterone supplementation can also affect the development of the fetus, causing some malformations in the spine, anus, limbs, and other parts of the fetus. Quantitative progesterone during pregnancy is necessary to maintain pregnancy. High concentration of progesterone has a sedative effect on the uterus, and it can relax the uterine muscle fibers and reduce excitability, as well as reduce the sensitivity of the pregnant woman’s uterus to contractin. Women should seek medical attention once any abnormalities occur in their body during pregnancy to avoid adverse conditions. In addition, women who are ready to get pregnant must do a good pre-conception checkup, and any abnormalities should be cured before getting pregnant, to provide a good environment for the future baby to be conceived.