What is a mucus plug?
- Reviewed by Toni Golen, MD, Editor in Chief, Harvard Women's Health Watch; Editorial Advisory Board Member, Harvard Health Publishing; Contributor
When you are pregnant, you are closely tuned in to bodily changes that may signify that labor is near. Losing the mucus plus may be an early signal that labor could begin soon.
What is a mucus plug, and what role does it play in pregnancy?
The mucus plug, also known as the cervical mucus plug, is a collection of thick mucus that forms in the cervix during pregnancy. The cervix is the bottom portion of the uterus; it connects the uterus to the vagina, or birth canal.
The mucus plug sits at the opening of the cervix and plays a role as a protective barrier, helping to prevent bacteria and other harmful substances from entering the uterus and endangering the developing fetus.
Mucus plugs and the onset of labor
Losing the mucus plug may be an early sign that labor is approaching. Other changes that signal labor is beginning include lightening (when the baby's head drops into the pelvis, and you may feel it becomes easier to take a deep breah), the amniotic sac opening (this is referred to as "water breaking"), light bleeding, and contractions.
When do you lose the mucus plug?
The timing of when a person loses the mucus plug varies. It's different for all people and for all pregnancies. The mucus plug can be lost weeks before labor begins or it can be lost just before labor, or even during labor itself. Most often, the mucus plug is lost in the later stages of pregnancy, or after 37 weeks of pregnancy. Some individuals never lose their mucus plug, or don't recognize when they do. This is also normal.
What does a mucus plug look like?
A mucus plug is typically thick and gel-like and either clear or pink in color. The plug can vary in size and consistency.
The mucus plug can be tinged with blood and may appear streaked with red, pink, or brown material. If your discharge suddenly becomes bright red and exceeds an ounce (about two tablespoons), contact your doctor immediately.
How can you tell that you've lost the mucus plug?
Losing the mucus plug is different for everyone. For some, the mucus plug is expelled in one piece. For others, the mucus plug comes out gradually in several pieces. Some individuals may not notice losing the mucus plug at all, or it may be lost during labor.
How long after losing the mucus plus does labor start?
While losing the mucus plug may be a sign that labor is near, it does not necessarily tell you exactly when. While labor could start within hours, it could also be days or weeks away. Think of the loss of the mucus plug as just one of many signs that your body is preparing for labor.
About the Author
Jenette Restivo, Health Writer; Assistant Director for Digital Content Creation and Engagement, Harvard Health Publishing
About the Reviewer
Toni Golen, MD, Editor in Chief, Harvard Women's Health Watch; Editorial Advisory Board Member, Harvard Health Publishing; Contributor
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