Mucus plug vs discharge: What does a mucus plug look like?

What is the mucus plug?

Similar to how your cervix produces cervical mucus during your menstrual cycle, it does so in pregnancy too. As the name suggests, the mucus plug is made up of mucus that forms in the cervix early in pregnancy. It works kind of like a seal, or plug, and helps to protect your baby by preventing harmful bacteria from entering the uterus [1, 2].

Once formed, the mucus plug stays in place for most of your pregnancy. During the last few weeks or days leading up to labor, the mucus plug comes loose and is discharged through the vagina as your body prepares to give birth [1]. 

What does the mucus plug look like?

Mucus plugs are made up of thick, sticky mucus that can feel jelly-like in consistency. They are typically odorless and often off-white or clear in color, but they can also be brownish, pinkish, or reddish if there’s blood mixed in [3].

Each mucus plug covers the entire cervix and is quite large compared to other cervical mucus “blobs” that you may have noticed at other times (for example, during your fertile window in your menstrual cycle). The whole thing measures around 1-2 tablespoons (roughly 10 g) in volume [1]. However, a mucus plug doesn’t always come out all at once, which can make it a bit tricky to tell apart from other cervical mucus.

How to tell the difference between mucus plug and discharge

Because it’s common to have more discharge during pregnancy [3], it can sometimes be hard to know if you’re looking at regular discharge or your mucus plug. So, let’s go through some key differences between the two:

• Color: The color can be a clue — the mucus plug can have blood in it (but doesn’t always) which can make it look brown, pink, or reddish. Regular discharge during pregnancy doesn’t have blood in it and is typically white or light yellow in color.
• Texture: The mucus plug is thicker and stickier compared to other discharge, which tends to be thinner and more slippery.
• Timing: The mucus plug typically comes out during the last few weeks of pregnancy, in week 37 or later, while you’ll have other discharge throughout your pregnancy. You may lose the mucus plug all at once in one large clump, or it can come out in smaller pieces which can be more tricky to tell apart from normal discharge — you may just notice more discharge than before [3, 4].

Mucus plug vs bloody show

If you’ve looked for information about the mucus plug or talked about it with others, you may have come across the term “bloody show”. The two are sometimes used interchangeably, and while they are linked, there is a slight difference between them. 

The mucus plug refers specifically to the mucus that seals the cervix during pregnancy. Losing the mucus plug is a sign that labor is on its way, and it happens when the cervix starts to open and become thinner in preparation for childbirth [5]. Bloody show is another early sign of labor and it’s also related to how the cervix changes in preparation for labor. It refers to light bleeding that can happen when small blood vessels break as the cervix dilates [6]. Because the mucus plug comes loose when the cervix dilates, this bleeding can mix with the mucus plug so that it looks a bit bloody when it comes out — which is why the mucus plug is sometimes called a bloody show as well.

When do you lose the mucus plug?

Typically, you’ll lose your mucus plug at some point after you’ve reached week 37 of your pregnancy, although the timing varies from person to person. It’s considered one of the early signs of labor, but it’s important to know that losing your mucus plug doesn’t necessarily mean that labor will start soon — some lose their mucus plug a few weeks before they give birth, while others only lose it a few days or hours before, or even during labor itself [3].

How do you know if you’ve lost your mucus plug?

If you notice a clump of mucus in your underwear or when going to the bathroom towards the end of your pregnancy, it may be your mucus plug. For some, it comes out all at once and that’s easier to spot since it will be a larger and thicker blob compared to other discharge you see during pregnancy. 

You can also lose your mucus plug more gradually so that it comes out in small pieces over time, which can make it hard to distinguish from other discharge. Not everyone will notice when they lose their mucus plug, so don’t worry if you haven’t.

What causes the mucus plug to come out?

Losing the mucus plug is a natural part of pregnancy as your body prepares to give birth, so it will happen eventually for everyone. There are two main reasons why the mucus plug comes out at this point, and both have to do with how the cervix changes as labor approaches:

• Dilation: The cervix will start to dilate, or open, during the weeks or days before labor starts. This causes the mucus plug to loosen and eventually be dislodged and come out through the vagina. By the time you’re ready to start pushing if you have a vaginal delivery, the cervix will have dilated to 10 cm.
• Effacement: As labor approaches, the cervix will also become thinner — this is called “cervical effacement”. When it’s time to start pushing, the cervix will be 100% effaced [5].

Can I go into labor without losing my mucus plug?

Yes! Losing the mucus plug isn’t a definitive sign of when labor will start. Some lose their mucus plug weeks or days before, while others don’t lose the mucus plug until labor has already started [1]. And some don’t notice it happening at all — everyone is different.

Losing the mucus plug early in pregnancy

Losing the mucus plug early can be an indication of preterm labor [1], so you should call your healthcare provider right away if you think you’ve lost the mucus plug before week 37, especially if you’re also having other symptoms of preterm labor like contractions or vaginal bleeding. The cervix can continue to produce mucus even after the mucus plug is lost [7], but you should still contact your doctor as a precaution so that they can determine the next steps.

What should I do after losing the mucus plug?

In most cases, if you’re 37 weeks or more into your pregnancy, you don’t need to do anything in particular when you lose the mucus plug (unless you’ve been given specific instructions by your healthcare provider). Even though it can still be a while before labor starts, this is a good time to prepare your hospital bag and make sure you have everything ready for when it does. However, if you’re less than 37 weeks along, or you’re having contractions or other signs of labor, you should call your healthcare provider to see if you need an examination [3].

Things to avoid after losing your mucus plug

Again, if you’re in week 37 or more, you don't need to worry about changing your behavior or steering clear of anything new at this stage of pregnancy unless you're told otherwise by your doctor. It’s okay to go about life as you normally would, and you can have sex even after you’ve lost the mucus plug if you want [7]. That said, if you’re feeling unsure or have any questions, you can always check in with your healthcare provider. 

How soon will I go into labor after losing my mucus plug?

While losing the mucus plug is a sign that your body is getting ready to give birth, it’s not possible to say exactly when it will happen. For some, it may still be a couple of weeks until labor starts, while for others it can be a matter of days or even hours.

If you notice that you’ve lost your mucus plug, now is a good time to start keeping an eye out for other signs of labor, such as:  

• Contractions: Labor contractions come at regular intervals that get closer together as time goes on, and they also get progressively stronger. You may feel them in your stomach or lower back. Especially in late pregnancy, you may also have experienced Braxton Hicks contractions, which can be confused with labor contractions. However, these come and go and don’t indicate labor is starting. It’s a good idea to time your contractions to know when to go to the hospital.
• Water breaking: Your baby sits in a fluid-filled sac in the uterus which breaks shortly before labor starts — this is often referred to as your water breaking. As the fluid comes out through the vagina, you may feel it as a gush or a slow trickle.
• Lightening: As labor approaches, your baby will get into position lower in your pelvis with its head down. When this happens, the pressure on your diaphragm is reduced which can lead to a “lightening” feeling. You may instead feel pressure in your pelvis and like you need to use the bathroom since the baby is now pressing down on your pelvis, bladder, and bowels [8].

When to talk to a doctor

Losing your mucus plug usually isn’t a cause on its own to call your healthcare provider (as long as it’s after week 37 and you haven’t received other instructions). That said, it’s good to keep an eye on your discharge during pregnancy as it can give an indication that there’s something else going on. For example, if you notice a foul smell, it can be an indication of infection or bacterial vaginosis which can be a risk factor for preterm labor if it’s not treated [2]. Reach out to your healthcare provider if you notice any of the following:

• Foul-smelling discharge
• Green, yellow, or gray discharge
• Pain in or around your vagina or vulva
• Redness or swelling 
• Itchiness [9, 4]

You should also contact your healthcare provider right away if:

• You’re bleeding heavily (more than a period)
• You lose the mucus plug before week 37
• Your water breaks
• You’re having contractions every five minutes or less
• Your baby is moving less than usual
• You have constant pain between contractions [8, 10]

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