When does the mucus plug come away?

Questions about the mucus plug are on many mums-to-be’s minds, yet the topic rarely comes up during routine check-ups. It can bring uncertainty or worry, so it helps to understand it a little. The most common questions are:

What is the mucus plug? What is its role during pregnancy? Does everyone have one? When will it come away? How will I notice? Is it painful when it comes away? Does it really mean labour is starting? Should I worry if it comes away early? What should I do then? Does infection risk rise once it is no longer in place? Will I be able to tell it apart from amniotic fluid or vaginal discharge? Can it come away in several pieces rather than in one go?

Mums-to-be often look out for the mucus plug as the due date approaches. It is one of pregnancy’s notable signs because it can indicate your baby is on the way. Not everyone sees it though. It is possible to go through several pregnancies without ever noticing it, simply because it came away at a stage when you did not see it.

It also raises questions because we want to know what it does and how much time might be left between seeing it and labour starting. With your first baby you may not be sure what the mucus plug is. You may only have heard stories and half-answers from others. To help you recognise it and to give clear answers, here is a closer look at its role and the ways it may come away

What is the mucus plug?

Our bodies are well prepared when it comes to protection, and pregnancy is no exception. The mucus plug is one of the pregnancy’s quiet guardians. To protect the uterus and baby from outside infection, the body produces and collects a thick, jelly-like substance in the cervix, creating a natural barrier between the uterus and the outside world. Its gel-like structure fills the cervical canal and helps guard against infections that, in some cases, are linked with preterm birth and other complications.

Preventing ascending infections is important throughout pregnancy, so the mucus plug acts as a defensive line. It is a mucus that can be streaked with blood and, under the influence of progesterone, it becomes thicker in pregnancy. Progesterone is also known as the corpus luteum hormone. Among other roles, it helps thicken the uterine lining so the fertilised egg can implant in this nutrient-rich environment. It supports the continuation of pregnancy and helps reduce the risk of early miscarriage.

How can we recognise the mucus plug?

Its appearance and texture can vary a lot, which is why some mums-to-be never notice it coming away. It should not be confused with amniotic fluid or vaginal discharge. Amniotic fluid is clear and released in larger amounts, while the mucus plug is not fluid. It is sticky, jelly-like mucus that may be mixed with a little blood.

You might not see it at all because it does not always come away at a time when you would notice. The name suggests something solid, but it is actually slippery, jelly-like, gluey or sometimes more liquid. The colour can be whitish, pinkish, brownish, red or rusty. Because of this, it may be quite thick, but it can also look more like a discharge, which makes it easier to miss.

Its appearance varies. Some mums find a jelly-like clump in their underwear, while others notice it in several pieces over a few days. Some women who have given birth more than once have never seen it. However it appears, it indicates cervical change, but it does not necessarily mean labour is starting right away.

When does the mucus plug come away?

The exciting question is usually how long after the mucus plug comes away labour might begin. It generally appears in the final weeks of pregnancy as the cervix softens and ripens. It can also show up during the latent phase of labour. It is just as possible that you will not notice it at all. Labour might start a few hours after it appears, or it may still be several days away.

In the latent phase, the cervix begins to shorten and open, and the baby’s head settles into the pelvic brim. Many mums do not really notice this phase. Contractions are not long yet, often 20 to 40 seconds, and not painful. You may feel active, carry on with family tasks and finish packing your hospital bag.

Cervical dilation does not always mean labour will begin that day or within a few hours. It can still be days before labour truly starts. The mucus plug can come away at a point in cervical change that the labouring mum simply does not notice.

If the mucus plug appears before 37 weeks, tell your doctor or midwife. Seek help at once if you notice bleeding. Because cervical change can be accompanied by light bleeding or brownish, pink-red spotting, ask your clinician if you are unsure whether what you are seeing could be a concern.

References:

NHS — Signs that labour has begun and Mucus plug (parent-facing
guidance on what it is, colours, and when to call).

Tommy’s (UK charity) — What is the mucus plug and what does it mean?