A mucus plug is thick mucus that forms within the cervical canal during pregnancy. It acts as a protective barrier, sealing the uterus to prevent infection from reaching the fetus. This natural seal forms early in pregnancy due to increased hormones, particularly progesterone. It remains in place for most of pregnancy, safeguarding the baby.
How the Mucus Plug Is Lost
The mucus plug can be lost gradually or all at once. This expulsion occurs as the body prepares for labor, when the cervix begins to soften, thin (efface), and open (dilate). These changes in the cervix cause the mucus plug to dislodge and move into the vagina. Sometimes, the loss of the mucus plug is accompanied by a small amount of blood, often called “bloody show.” This happens when tiny blood vessels in the cervix rupture as it begins to expand.
Appearance and Characteristics
The mucus plug’s appearance can vary. It is a thick, jelly-like substance, often clear, off-white, yellowish, brownish, or pink. It may also be streaked with a small amount of blood, giving it a reddish tint. The consistency is often described as stringy or sticky, resembling mucus from a cold. It can be 1 to 2 inches long or about 1 to 2 tablespoons in volume, though it may also come out in smaller pieces.
What Losing It Means for Labor
Losing the mucus plug is a sign that the body is preparing for labor, as it indicates changes in the cervix, such as softening and dilation. However, it does not mean that labor is immediately imminent. Labor could begin hours, days, or even weeks after the mucus plug is lost. Some individuals may not even notice losing their mucus plug, especially if it comes out gradually or during active labor. The body continues to produce cervical mucus, and the amniotic fluid provides ongoing protection against infection even after the plug is gone.
When to Contact Your Doctor
While losing the mucus plug is a normal part of late pregnancy, there are specific situations when you should contact your healthcare provider. If you lose your mucus plug before 37 weeks, call your doctor, as this could be a sign of preterm labor. Contact your doctor immediately if you experience a significant amount of bright red blood, more than just streaks, as this could indicate a more serious complication like placenta previa or placental abruption. Seek medical attention if the loss of the mucus plug is accompanied by other concerning symptoms, such as strong, regular contractions, a gush of fluid (indicating ruptured membranes), or severe pain. If you are past 37 weeks and have no other concerning symptoms, you can mention the loss of the mucus plug at your next prenatal appointment.