Progesterone is a female hormone and the most important progestogen for women. It supports pregnancy and the formation of infant embryos, and is closely related to fertility. For expectant mothers, checking progesterone levels during pregnancy is very important. So, what is the normal value of progesterone at 40 weeks of pregnancy?
Under normal circumstances, the normal value of progesterone at 40 weeks of pregnancy is around 26ng/ml in amniotic fluid. As long as the progesterone level of pregnant women is ≥ 25ng/ml, it is considered normal. A progesterone level of 15-25ng/ml is a manifestation of luteal insufficiency and requires progesterone treatment, with a relatively high success rate. Progesterone levels ≤ 15ng/ml are very dangerous and have a higher probability of miscarriage.
According to research, progesterone levels fluctuate regularly depending on pregnancy status and duration. Before 7 weeks of pregnancy, the normal range of progesterone is between 18-22ng/ml in the blood (with a mean of 24ng/ml in the blood); After 7 weeks of pregnancy, progesterone levels gradually increase until reaching the highest blood level of 202.0 ± 47.0ng/ml at 35 weeks of pregnancy.
Afterwards, it gradually decreases and approaches pre delivery, around 40 weeks, reaching amniotic fluid levels of 26ng/ml, or 81.1nmol/L. Progesterone can cause uterine smooth muscle cells to become hyperactive, reduce their activity and conductivity, inhibit uterine contractions, and keep them in a quiescent state, which is beneficial for embryo growth. Low progesterone levels pose certain risks for pregnant women, and women must pay attention to checking progesterone levels during pregnancy to ensure the safety of the fetus.
