A mucus plug is a collection of mucus that forms in the cervical canal in early pregnancy. It prevents bacteria or infection from entering your uterus and reaching your baby. As your cervix prepares for labor, you will lose the mucus plug. This is a normal and common symptom in late pregnancy.
The mucus plug is a thick piece of mucus that blocks the opening of your cervix during pregnancy. It forms a seal to prevent bacteria and infection from getting into your uterus and reaching your baby. Think of it as a barrier between your vagina and your uterus where your baby is. You will lose this plug as your cervix begins to dilate (open) and efface (soften and thin) in preparation for labor.
As your body prepares for labor, your cervix begins to soften, thin, and open. This causes the mucus plug to dislodge from your cervix. The mucus is pushed out into your vagina. This is considered losing your mucus plug.
Most people don't lose their mucus plug until after 37 weeks of pregnancy. In some cases, losing the mucus plug happens days or weeks before your baby’s due date. Some people don't lose it until they're in labor. If you lose your mucus plug sooner than 37 weeks of pregnancy, contact your healthcare provider as a precaution.
The look, size and texture will vary. The mucus plug is usually:
You may lose your mucus plug in one glob or you may lose it gradually over time and never notice it. A small amount of blood is common, but severe bleeding may be a sign of placental abruption, placenta previa or other pregnancy complications. Contact your healthcare provider if you notice heavy bleeding during pregnancy.
Increased vaginal discharge is normal in pregnancy. Vaginal discharge is usually thin and light yellow or white in color. Discharge from the mucus plug is thicker, more jelly-like and there is more of it. It can also be tinged with red, brown or pink blood.
They are closely related but slightly different. Both occur late in pregnancy as your cervix dilates in preparation for labor. Mucus plug discharge is stringy and jelly-like. It is a collection of mucus. A bloody show is bloody discharge that can contain small traces of mucus. The bloody show is a result of blood vessels rupturing in your cervix as it expands.
Losing your mucus plug generally means your cervix has started to dilate, efface or both. It means labor is around the corner, but there is not an exact time for how soon after other labor symptoms will start. In some cases, you may already be in labor when you lose your mucus plug.
The length of time between losing your mucus plug and going into labor can vary. In some cases, you may go into labor within hours or days, while other times, you may not go into labor for a few weeks.
The most noticeable sign is seeing mucus in your underwear or on toilet paper. Not all people know when they lose their mucus plug. This is because it comes out slowly over time instead of all at once.
There are a few things that cause you to lose your mucus plug:
If you suspect you have lost your mucus plug and are less than 37 weeks pregnant, you should contact your healthcare provider. They could be concerned and want to examine your cervix.
Losing the mucus plug can be one sign that labor is near. There are several other signs labor is coming. You should monitor yourself for these other signs:
There are no side effects from losing your mucus plug. It's a normal part of pre-labor. Losing your mucus plug can be accompanied by other symptoms of labor.
If you suspect you lost your mucus plug before 37 weeks of pregnancy, it's best to contact your healthcare provider. This could be a sign of early labor or other pregnancy complication.
Take note of what your mucus plug looks like — color, size and consistency. This can help your healthcare provider determine if it was your mucus plug. If you are 37 weeks into pregnancy and feel no labor symptoms, your healthcare provider may have no concerns. If you are less than 37 weeks pregnant or having contractions, your healthcare provider may want to evaluate you.
You can go into labor without losing your mucus plug. The timing between labor and mucus plug discharge can vary. Some people lose their mucus plug after other labor symptoms begin. In some cases, losing the mucus plug is the first symptom.
You can dilate to a certain degree and not lose the mucus plug, but it will come out eventually. All pregnant people will have a mucus plug protecting the uterus from bacteria. It will always fall out before the baby is delivered.
Yes, the mucus plug can regenerate in your cervix. It's possible to lose parts of your mucus plug and then lose more later. This is because your body is constantly creating vaginal discharge and mucus during pregnancy.
If you are unsure if your discharge is the mucus plug, you can contact your healthcare provider. Be prepared to describe the discharge. Losing the mucus plug is a normal progression of labor and usually not harmful.
If any of the following occur, you should contact your healthcare provider right away:
A note from the Cleveland Clinic
Discussing the signs of labor with your healthcare provider can be helpful and comforting during the last weeks of pregnancy. It's important to talk to your care team if you have questions about any of your symptoms.
Last reviewed by a Cleveland Clinic medical professional on 07/06/2021.
Learn more about our editorial process.