Progesterone during pregnancy: role, levels, and effects on the body

Progesterone is the most important hormone for a successful conception, the implantation of an embryo in the context of IVF (in vitro fertilization) and the normal development of a pregnancy. It is produced by the adrenal cortex, the ovarian corpus luteum, and the placenta, and plays a key role in preparing a woman's body to carry a baby to term.

Sources and levels of progesterone during pregnancy

As pregnancy progresses, the placenta becomes the main source of progesterone production. Its levels vary by trimester:

• First trimester: 80-140 nmol/liter;
• Second trimester: 1900-8200 nmol/liter;
• Third trimester: 6500-23000 nmol/liter.

The physiological decrease in progesterone levels occurs between the 6th and 9th week of pregnancy. During this period, the risk of miscarriage increases, necessitating closer monitoring by specialists.

Effect of progesterone on a pregnant woman's body

Progesterone has many functions, but its excess or deficiency can lead to certain complications:

Positive effects:

• Facilitating the implantation and growth of the embryo;
• Preparing the endometrium for pregnancy;
• Reducing uterine tone, preventing premature labor;
• Stimulating the growth of mammary glands for lactation;
• Supporting the immune system, preventing rejection of the fetus.

Possible adverse effects:

• Swelling and preeclampsia: fluid retention in the body increases the risk of edema and gestosis.
• Disruption of carbohydrate metabolism: the glucocorticoid activity of progesterone promotes the formation of glucose from non-carbohydrate compounds, which increases the burden on the pancreas and the risk of gestational diabetes.
• Intrahepatic cholestasis: progesterone can slow bile flow, causing bile stasis and damage to liver cells (hepatocytes), which manifests as skin itching and other symptoms.

Progesterone and maintenance of pregnancy

Progesterone plays a crucial role in maintaining pregnancy by fulfilling the following functions:

• It promotes stable pregnancy development;
• It prevents the risk of miscarriage in women suffering from corpus luteum insufficiency;
• Strengthens the closure function of the cervix, preventing its premature opening;
• Often used in pregnancies resulting from assisted reproductive techniques (IVF in vitro fertilization, IVF with egg donation, IVF with double donation, etc.).

Progesterone is the most important hormone of pregnancy, influencing its development and the success of the pregnancy. Its levels must be continuously monitored, especially in women undergoing infertility treatment or at risk of premature pregnancy interruption. For any questions regarding the norm of progesterone and its effects on the body, it is recommended to consult a gynecologist-obstetrician.

Further information on diagnosis and treatment is available at the Natuvitro clinic.