What does passing of the mucous plug mean?

To understand the process of passing of the mucus plug, you should recollect facts about the mucus plug formation and its function. The plug is a clot of mucus that fills the uterine cervix during pregnancy. Mucus in the uterus is produced under the influence of hormones. Production of estrogen and progesterone, which are called pregnancy hormones, leads to significant changes inside the uterus and vagina. Together with the intensified blood flow this promotes increased production of secretion. As a result the amount of female vaginal discharges increases, too.


The mucus plug forms from the very moment of impregnation. The amount of mucus increases, it becomes thicker and thicker and eventually forms a plug that seals the uterine cervix. The plug occupies the entire space between the cervix walls from its entrance, 4-5 cm deep. As new mucus is produced, the the excessive material passes in the form of discharge in small quantities, and fresh mucus takes its place in the cervix.

The plug serves to protect the fetus from infections that can penetrate to the uterus from the outside. Infection can easily get into the uterus through the vagina during sexual intercourse or during bathing. The plug doesn’t just physically block the way to infection, but it contains antibodies that help the immune system to fight pathogens.

Losing your mucus plug

From the moment of fertilization and up to 38 weeks of pregnancy progesterone is actively produced in the woman’s body, since exactly this hormone is responsible for child bearing. In the normal course of pregnancy during all this time the uterine cervix is ​​closed tightly by the plug until the level of the hormone is very high.


After 38 weeks of pregnancy the body stops producing progesterone, but production of another hormone, estrogen, increases. This hormone is needed to prepare the body for delivery. Under the influence of estrogen the uterine cervix becomes softer, the pelvigenital canal begins to open and the plug in the cervix becomes thinner before discharge.

So, discharge of the plug is one of the signs of labour during pregnancy meaning that the body is ready for delivery. When losing mucus plug at 39 weeks you may not worry since the gestational age is adequate for giving birth to a healthy baby. Also you should bear in mind that the plug may come out a few weeks before labor. On average, it passes a few days before labor, but it can come out 2 weeks or 2 hours before it. Besides, some women lose the plug during labour, so you shouldn’t worry if you feel contractions still having no signs of discharge. On the other hand, you shouldn’t think that losing mucus plug at 38 weeks means labour will begin immediately. If you have no other signs of labour (like contractions or bursting of waters), then you have enough time to prepare for the upcoming event.

But losing mucus plug at 34 weeks is a reason for concern, since it can mean premature birth. In this case you should inform your doctor immediately to take appropriate measures.

Regardless of gestational age contact your doctor and inform him of the vaginal discharges, as it will help the doctor to properly assess your condition.

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One comment

  1. My step daughter is 32 weeks and just lost her mucus plug! Does this mean she will more then likely not make it to her due date of oct 21st?

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