As the name implies, a mucus plug is basically a big blob of mucus blocking the top of your cervix to protect your baby from germs. "The mucus plug seals the opening of the cervix during pregnancy, similar to a cork, forming a protective barrier along with the amniotic sac," says Clara Ward, M.D., a maternal-fetal medicine physician with McGovern Medical School at UTHealth/UT Physicians in Houston, Texas. "Antibodies present in the mucus neutralize bacteria, viruses, and other causes of disease." The hormone progesterone, she says, makes the mucus nice and thick.
As you near the end of pregnancy and your body starts getting ready to push everything out during labor, your mucus plug is the first thing to go. "In the last days to weeks of pregnancy the mucus plug is lost as the cervix starts to soften, shorten, and even dilate in the process of preparing the cervix for labor," says Amy VanBlaricom, M.D., medical director of operations at Ob Hospitalist Group, a nationwide OB-GYN hospitalist employer. "These preparations of the cervix essentially push out the plug of mucus that has accumulated there."
So what does your mucus plug look like, and how do you know if you've lost it? Also, how can you tell the difference between your mucus plug, pregnancy discharge, and a bloody show? Here's what you need to know.
What Does a Mucus Plug Look Like?
For some women, the mucus plug comes out all at once. "It looks like a stretchy glob, similar to what may come out of your nose," says Dr. Ward. "It can be clear, yellowish white, beige, brown or pink, or tinged with red or brown streaks of blood."
For other women, it comes out gradually, and you may not even know it's happened; or you may only see it when wiping after going to the bathroom. "Not all women notice they have lost it, as it can blend in with the other increased secretions that lubricate the vagina in the late stages of pregnancy," says Dr. VanBlaricom, who is based in Seattle, Washington.
How Do I Know If I Lost My Mucus Plug?
The mucus plug might come out while using the bathroom, or you may simply notice it in your underwear. It can also be released slowly over several days. Not every woman will notice when their mucus plug comes out, and that's also perfectly fine, adds board-certified nurse midwife Kristin Mallon of Integrative Obstetrics in Jersey City, New Jersey.
Is It Your Mucus Plug or Discharge?
When it comes to the mucus plug, "some women don't know what to look out for," says Mallon. "They could be having normal discharge during pregnancy and mistake it for an early release of the mucus plug." In addition, mucus could stem from a yeast infection, bacterial vaginosis, or a sexually transmitted disease (STD). So how do you tell the difference?
For starters, the mucus plug is gooey, gelatinous, and yellowish-white in color (sometimes with tinges of pink or brown). Normal pregnancy discharge tends to be thin, mild smelling, and clear or milky white. Discharge from a yeast infection is usually yellow or white, thick, and chunky like cottage cheese. Bacterial vaginosis produces fishy-smelling discharge that's most noticeable after sex, while other forms of yellow, green, or foul-smelling discharge could signal an STD. See your doctor if you suspect any type of vaginal infection.
Bloody Show vs. Mucus Plug: What\’s the Difference?
Losing the mucus plug sometimes gets confused with the unpleasantly-named "bloody show," which sounds like a horror movie but is also a totally normal early labor sign. "Bloody show refers to the passage of blood at the end of pregnancy; the cervix has many blood vessels that may bleed easily once the cervix starts to dilate," says Dr. Ward. "Bloody show can occur in conjunction with losing the mucus plug, but not always. It can sometimes mean that labor is closer, compared to if you are only seeing mucus."
Bloody show may also be more blood than mucus, explains Dr. VanBlaricom, and even have a flow like a period. And because bloody show can represent more advanced changes in your cervix, she recommends calling your doctor, especially if you are preterm or have other pregnancy-related complications.