Will Mucus Plug Regenerate?

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Key Takeaways:

  • The mucus plug is formed in the cervix during pregnancy and acts as a protective barrier.
  • It’s normal to lose parts of the mucus plug throughout pregnancy as more mucus is secreted.
  • Yes, the mucus plug can regenerate and replace lost parts as long as some remains in the cervix.
  • Losing the entire mucus plug may signal the start of labor within days/weeks.
  • Partial losses of the plug are common and not necessarily concerning before 37 weeks.

What is the mucus plug and its purpose?

The mucus plug is a collection of cervical mucus that fills and seals the opening of the uterus during pregnancy. It forms in the cervix, which is the lower part of the uterus that connects to the vagina.

The main purpose of the mucus plug is to provide a protective barrier against infection ascending into the uterus from the vagina. It helps block bacteria and other pathogens from entering the amniotic sac and potentially harming the developing baby.

The mucus plug is often referred to as the “seal” that keeps the uterus sterile during pregnancy. It contains antiseptic biochemicals such as immunoglobulins, lactoferrin, and leukocytes which all have antibacterial properties. The plug’s thick gel-like consistency also physically plugs the cervical canal, providing a sticky barrier.

How does the mucus plug form during pregnancy?

The mucus plug starts developing early on in the first trimester of pregnancy. Increased estrogen levels cause the cervix to produce and secrete more mucus.

The mucus accumulates and sticks together, adhering to the walls of the cervical canal. As more mucus is produced, the mucus plug grows in size and blocks off the opening of the cervix.

By the third trimester, the mucus plug can be between 2-4 cm thick completely filling the cervical canal. The mucus takes on a thick, rubbery texture often described as resembling egg whites.

The plug may be white, yellowish, or tinged with a little blood. The blood comes from small blood vessels that form in the cervix during pregnancy.

Is it normal to lose parts of the mucus plug during pregnancy?

Yes, it is very common and normal to lose bits and pieces of the mucus plug throughout pregnancy. As the cervix produces more mucus, parts of the older mucus plug can loosen and be expelled.

According to a study in Midwifery, over 90% of women reported losing parts of their mucus plug during pregnancy, most commonly in the third trimester.

Losing fragments of the mucus plug is not necessarily a concern. The cervix continues secreting fresh mucus which can regenerate the mucus plug and replace any lost portions.

Typically, partial losses appear as thick mucus discharge that may be tinged with blood. Small losses may occur after intercourse, vaginal exams, bowel movements, or physical activity. Losing a little mucus doesn’t mean labor is imminent.

Can the mucus plug regenerate if parts are lost?

Yes, the mucus plug has the ability to regenerate even after partial losses. Since the cervix keeps producing mucus throughout pregnancy, the mucus plug can replenish itself multiple times.

Think of the mucus plug as continually being formed by newer mucus pushing out older mucus. Losing a piece just allows newer mucus to take its place.

As long as some amount of the mucus plug remains intact in the cervix, the cervix can continue secreting mucus to regenerate the lost portions.

Even after losing parts of the plug, the remainder is still able to provide an effective barrier for blocking infection in most cases.

Is it a problem if the entire mucus plug comes out?

Losing the entire mucus plug is more concerning because it leaves the cervix open and vulnerable to infection. It also often signals that labor will be starting soon.

When the whole mucus plug dislodges at once, it typically looks like a large amount of mucus tinged with blood. This is referred to as the “bloody show.”

According to a study in the Journal of Reproductive Medicine, 51% of women went into labor within 48 hours of losing their entire mucus plug. For most women, labor began within 7 days.

So losing the entire mucus plug is considered a sign that the cervix is preparing for delivery. However, it doesn’t guarantee that labor is imminent. Some women can regenerate a mucus plug and continue pregnancy for days or weeks after losing one.

Should you call the doctor if you lose your mucus plug?

It’s a good idea to contact your healthcare provider if you notice significant changes with your mucus plug, such as:

  • Losing large amounts of the plug at once
  • Losing all of the mucus plug at one time
  • Noticing a foul odor or unusual color to the mucus
  • Losing the plug earlier than 37 weeks pregnant

Your provider can examine you and check for dilation of the cervix. They may test for infection if the mucus smells foul.

If you lose your mucus plug before 37 weeks, it’s considered preterm premature rupture of membranes (PPROM). This signals a higher risk for preterm labor or infection.

However, minor mucus discharge with no odor, color, or other symptoms is usually not concerning. Let your provider know at your next visit. Monitor for labor signs.

What happens to the mucus plug before labor begins?

In the weeks before labor, the mucus plug begins to loosen up in preparation for delivery. As the cervix starts thinning out (effacing) and opening up (dilating), the mucus plug can detach.

The hormone relaxin also causes the cervical tissues to soften, which makes the plug more likely to dislodge. The cervix may dilate enough that the entire mucus plug is expelled.

Losing the mucus plug signals that the cervix is changing and getting ready for birth. But keep in mind that labor onset can still vary widely after losing a plug.

It’s also possible for labor to begin with the mucus plug still intact. Sometimes the cervix dilates rapidly, and a woman’s water breaks before the plug has a chance to come out.

Does the mucus plug form again after giving birth?

No, the mucus plug does not regenerate after delivery. It is only present during pregnancy when higher estrogen levels cause increased cervical mucus production.

After birth, the cervix closes back up and mucus production decreases substantially by about 6 weeks postpartum. Estrogen and progesterone levels plummet.

The cervix no longer needs to produce copious amounts of mucus to form a protective barrier. Without pregnancy, there is no need for the mucus plug.

Any cervical mucus present after giving birth is just normal minimal secretions. The regenerative mucus plug strictly serves a purpose during gestation and is not reformed.

When does the mucus plug form in subsequent pregnancies?

If a woman becomes pregnant again, a new mucus plug will start developing early in the first trimester. This again provides protection against infection for the new pregnancy.

Research has found that the mucus plug forms at around 7-9 weeks gestation in repeat pregnancies. However, it takes longer to fully develop and isn’t mature and well-formed until around 20 weeks.

In subsequent pregnancies, the cervix may produce less mucus compared to a first pregnancy. But eventually an adequate mucus plug does regenerate during the second and third trimesters.

Just like the first pregnancy, parts of the mucus plug may be lost and regenerate multiple times throughout. This is normal.

Key takeaways about the mucus plug:

  • The mucus plug provides an important protective barrier in the cervix during pregnancy.
  • It’s common to lose parts of the plug as pregnancy progresses and the mucus regenerates.
  • Losing the entire plug may mean labor will start within days or weeks as the cervix prepares to dilate.
  • Notify your provider if you lose all of your plug before 37 weeks or notice any abnormal symptoms.
  • After birth, the mucus plug does not reform since its only purpose is during pregnancy.

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