The role of progestogen in the prevention of preterm birth

The article was professionally consulted by Doctor Department of Obstetrics and Gynecology, Vinmec Hai Phong International General Hospital.

Premature birth is a condition that occurs when a baby is born before the 37th week of pregnancy. Premature babies are more likely to have health problems than full-term babies (born between 39 and 40 weeks of pregnancy). According to the results of many studies, a progestogen can help prevent premature birth for some women.

Preterm birth is a condition that occurs when a baby is born before the 37th week of pregnancy. Approximately 70% of preterm births occur spontaneously, the remaining 30% of preterm births can be caused by medical decisions or are the result of diseases in the mother or fetus (pregnancy). seizures, placenta previa, intrauterine growth retardation, etc.).
Premature birth is a leading cause of neurological disability and infant mortality. Factors that increase the risk of preterm birth include: previous preterm birth, vaginal bleeding, multiple pregnancy, low body mass index (BMI), genital tract infection,...

Progestogen is 1 of 5 steroid hormones. Progestogens are divided into two groups, exogenous (progestin) and endogenous (progesterone). Progesterone is a hormone made by the body that plays an important role during pregnancy. In the early stages, progesterone helps the uterus to grow and reduce contractions, helping to reduce the risk of miscarriage (because if uterine contractions occur in the early stages of pregnancy, it can lead to miscarriage). died in utero before 20 weeks).
For the later stages of pregnancy, progesterone helps the mammary glands develop to be ready to secrete milk and helps the lungs work better to provide more oxygen for the developing fetus. At the same time, progesterone also modulates the immune response by reducing the production of proinflammatory and smooth muscle relaxant cytokines, thereby blocking the action of oxytocin and inhibiting the formation of the uterine smooth muscle contraction response. . In particular, progesterone also prevents the self-destruction of fetal membranes.
There are 2 forms of progesterone use in the prevention of preterm birth:
Vaginal progesterone Reduces the risk of preterm birth in women with a singleton pregnancy and a short cervix. A short cervix means that the cervical canal is shorter than normal (<20mm), leading to an earlier opening of the cervix, before the baby is ready to be born. Your doctor may prescribe you to use progesterone vaginal gel, suppository or capsule.
The advantage of vaginal progesterone is that it is highly bioavailable in utero because of its effect on the uterus before first-pass metabolism in the liver. However, vaginal progesterone can also cause vaginal irritation and discomfort, but with less systemic side effects. And because vaginal progesterone has a half-life of about 13 hours, it is usually given daily, at a dose of 90 mg - 400 mg;

Injectable Progesterone Reducing the risk of preterm birth in case of a singleton pregnancy with a history of preterm birth, this type of progesterone contains 17 alpha-hydroxyprogesterone caproate (also known as 17P). Doctors usually prescribe injectable progesterone for pregnant women starting from 16-24 weeks and until 36 weeks of pregnancy. The vaccine is either Makena (a brand name drug) or a compound (used for people who are allergic to Makena ingredients). When injecting the drug, pregnant women may feel discomfort at the injection site.
Note: Progestogen treatment is not applicable in case of multiple pregnancies but only for singletons.
Premature birth is a major cause of perinatal mortality and other morbidity. Progestogens play an important role in preventing spontaneous preterm birth in two groups of women: women with a history of preterm birth, singleton pregnancies, and singleton pregnancies with a short cervix. When using Progestogen to prevent premature birth, pregnant women need to strictly follow the doctor's instructions.