The mucus plug

The cervical mucus plug is a compact piece of mucus that gathers at the opening of the pregnant woman’s cervix. It serves as a barrier between outside bacteria and the developing fetus inside the uterus, and its antibacterial properties protect the fetus from infection.


Usually, the mucus plug looks stringy or sticky, and it can be clear or slightly blood tinged. It’s possible to not even notice that the plug has fallen out, because at the later stages of pregnancy there is already a change in vaginal discharge.

Exit from the body

When the body starts preparing for labor and the cervix starts to soften, the mucus plug loosens and falls out. Some women experience the plug falling out all at once, in a single compact ‘chunk’ of mucus. Others report clumps of it falling out over an extended time period. Either is completely normal and healthy, and doesn’t hurt or even feel like much at all.

Is it a sign of labor?

Loss of the cervical mucus plug doesn’t necessarily indicate that a woman will immediately go into labor. The mucus plug can fall out weeks before a woman delivers her baby. However, it can be a warning sign of preterm delivery. Any woman with bright red bleeding or persistent leakage of fluid or a large gush should contact their healthcare provider immediately if this occurs before week 37, as this could indicate that the cervix is dilating preterm.

If you have any questions about this, speak to your healthcare provider, as they will be able to discuss more about the mucus plug and its role in pregnancy.

Reviewed by the Ovia Health Clinical Team

  • Mayo Clinic Staff. “Signs of labor: Know what to expect.” MayoClinic. Mayo Foundation for Medical Education and Research, Jun 18 2016. Web.
  • “How to tell when Labor Begins.” ACOG. FAQ004 from the American College of Obstetricians and Gynecologists, May 2011. Web.
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