The mucus plug is a thick clump of cervical mucus that forms during pregnancy. The mucus plug helps block the cervix, which is the entrance from the vagina to the uterus. When a person loses their mucus plug, it may mean that labor will begin soon.

Labor typically starts within a few days or hours, though sometimes it may not start for several more weeks. Some people call the loss of the mucus plug “bloody show.”

In this article, learn more about losing the mucus plug, including how it may look and when to contact a doctor.

The cervix is a doughnut-shaped muscle that acts as the “door” from the vagina to the uterus. During pregnancy, it closes tightly to keep the fetus in place and help prevent infections from entering the uterus.

The cervical mucus plug offers additional protection from anything entering the cervix that could affect the developing fetus.

Cervical mucus changes throughout a person’s reproductive life and menstrual cycle, largely due to hormonal factors. Shortly after conception, progesterone causes cervical mucus to become denser, thicker, and more acidic, forming the mucus plug.

The main symptom of the mucus plug falling out is the sudden appearance of blood-tinged mucus. Some people experience labor symptoms, such as contractions, when this happens.

It is important not to confuse the loss of the mucus plug with other types of bleeding. While a small amount of bleeding is common in labor, excessive bleeding may warn of a hemorrhage, a placental abruption, or other complication.

Emerging research suggests that the role of the mucus plug is complex. The body’s ability to create a healthy mucus plug may even predict pregnancy outcomes.

The results of a 2013 study suggested that those at risk of giving birth prematurely were more likely to have issues with their cervical mucus. In these people, the mucus did not form as strong a barrier, potentially offering less protection.

As the body prepares for labor, the cervix “ripens,” which means that it gets softer and shorter and begins opening. The cervix eventually opens enough for the mucus plug to fall out.

Sometimes, the plug falls out all at once. A person may notice a large glob of mucus and blood. The plug can also come out in pieces over time, so the individual might see a small and periodic discharge of mucus and blood, or perhaps not even notice the change at all.

While losing the mucus plug typically means that labor is coming soon, there is no way to predict exactly when it will happen.

Some people only lose their mucus plug after labor has begun. Others experience labor a few hours after the mucus plug falls out, while some wait days or even weeks.

Labor is different for every person, especially in the early stages when contractions tend to be irregular or weak.

Some signs that a person might go into labor soon include:

  • changes in the shape, texture, or location of the cervix
  • an increase in cervical mucus
  • change in the position of the fetus, or a pregnant belly that looks as though it has “dropped

Some early signs of labor include:

As labor progresses, contractions typically become more prolonged and more regular. They may also feel different.

False and early labor contractions tend to affect only the front of the body, and they may weaken with movement or if a person gets into water.

Real labor contractions typically begin in the back or at the top of the uterus and feel progressively stronger. They do not stop when a woman moves or takes a shower.

Many people notice blood-tinged mucus discharge after losing their mucus plug. However, because it can come out in small pieces over time, some people may not notice any changes or experience any symptoms after losing their mucus plug.

In some cases, a person may also experience other early signs of labor after losing their mucus plug, including:

  • period-like cramps
  • contractions
  • pelvic pressure
  • low back pain

If a person loses their mucus plug before 37 weeks of pregnancy, they should contact their doctor.

However, after 37 weeks of pregnancy, doctors do not typically consider losing the mucus plug harmful unless other symptoms accompany it, such as sudden bleeding, pain, or fever.

A person should contact their doctor if they have any concerns or experience other symptoms. Otherwise, they can mention it at their next appointment and use a pad or panty liner if the discharge continues.

Losing the mucus plug is not typically harmful. However, it may indicate a person is at risk of preterm labor if it happens before 37 weeks. A person should contact a doctor or midwife about any mucus-tinged blood that appears before their pregnancy reaches full term.

People should go to the emergency room immediately if they:

  • have sudden bleeding, especially with intense uterine pain
  • develop a fever
  • notice that the fetus stops moving or moves less frequently

People can contact a doctor if the following occur:

  • The pregnant person experiences a gush of fluid from the vagina. This is typically a sign that the membranes have ruptured. The “water breaking” often means labor is imminent.
  • The pregnant person has other symptoms of labor.
  • The pregnant person is at risk of preterm labor, or a doctor has instructed them to call immediately upon signs of labor.

Anyone unsure about whether they have lost their mucus plug should also call their doctor or midwife, and mention this at their next appointment.

Here are some frequently asked questions about mucus plugs and their answers.

How does losing a mucus plug look?

As the cervix starts to dilate, the mucus plug moves into the vagina. Though some people may not notice any changes, others expel the entire mucus plug or may notice a gradual increase in blood-tinged, clear, or pink vaginal discharge.

How dilated is a person when their mucus plug comes out?

Losing the mucus plug is a sign that the cervix has started to dilate, soften, and become thinner. However, the degree of dilation can vary, as a person can lose their mucus plug at any time during this process.

What are the signs that a mucus plug is leaking?

Increased vaginal discharge is one of the most common signs that a person has lost their mucus plug. However, while the mucus plug always comes out before delivery, some people may not notice any changes or symptoms.

What are things to avoid after losing the mucus plug?

If a person loses their mucus plug after 37 weeks of pregnancy and does not have any other symptoms or concerns, they typically will not need to take additional precautions unless advised by their doctor.

How long after losing the mucus plug does labor start?

Losing the mucus plug is often an early sign of labor. However, some people may not experience labor for several hours, days, or weeks after the mucus plug falls out.

What color is a mucus plug?

The mucus plug can range in color. It may be slightly bloody, clear, or pink.

Losing the mucus plug is a common symptom late in pregnancy. It typically means that labor will begin soon.

The mucus plug may look strange, and the presence of blood in it might be unsettling to some people. However, the loss of the mucus plug is not typically a medical emergency unless a pregnant person has other symptoms, such as significant bleeding or signs of preterm labor.

The end of pregnancy and the beginning of labor can be confusing and uncertain. A person might not know whether labor has begun, and they might wonder whether what appears to be a mucus plug is actually something else, such as abnormal bleeding.

A person should talk with a doctor or midwife during pregnancy about what signs warrant a visit or phone call. People may wish to check with a healthcare professional about any new or unusual symptoms.