When Does Labor Start After Losing Your Mucus Plug?

Pregnant Woman Looking at Stomach
Pregnant Woman Looking at Stomach

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When a woman gets pregnant, her body will release mucus to block the cervix and protect the uterine environment from infection, says board-certified nurse midwife Kristin Mallon of Integrative Obstetrics in Jersey City, New Jersey. The cervix (or mouth of the uterus) stays plugged with mucus to repel bacteria from the outside.

In late pregnancy, small amounts of uterine contractions start to open up the cervix, says Adeeti Gupta, M.D., FACOG, founder of Walk In GYN Care in New York, New York. "The cervix also softens due to hormonal changes, which leads to the opening of the cervix and release of the mucus plug," she adds. The loss of the mucus plug allows your baby to pass through the cervix more easily.

So how soon after losing your mucus plug does labor usually start? We spoke with experts to learn more.

Does Losing the Mucus Plug Mean Labor is Coming?

The mucus plug looks like a gelatinous blob, and it might resemble blowing your nose. It can be yellowish-white and tinged with red or brown streaks. You might discover it while wiping or in your underwear—or you might not notice it at all. If you do spot the mucus plug, however, labor is likely on its way.

"The loss of the mucus plug, especially when there's a little bit of blood, is usually a good indicator that labor is coming within one to three days," says Mallon. "But sometimes labor will come weeks after losing the mucus plug, so this guideline isn't 100 percent accurate." In other words, losing the mucus plug signals that labor is approaching, but you can't be sure exactly when the first contraction will hit.

Unless your water has broken, your baby is still protected even after the mucus plug falls out. "If you lose your mucus plug but don't go into labor for a while, it doesn't mean that Baby is in danger of infection," says Clara Ward, M.D., a maternal-fetal medicine physician with McGovern Medical School at UTHealth/UT Physicians in Houston, Texas. "Your cervix continues to produce mucus to replenish what is lost, and the amniotic fluid has many immunological agents that continue to protect Baby against infection."

What Should I Do After Losing the Mucus Plug?

After losing their mucus plug, women may be tempted to grab their hospital bag and run out the door. But Mallon advises against this. "A woman doesn't need to call her doctor in the middle of the night if her plug is removed, but she should report it the next day or at her next appointment," says Mallon.

Dr. Gupta adds that a woman should closely monitor her baby's movements after losing her plug. "If contractions start, time them," she says. "When they become regular—lasting at least 30 seconds and coming every three-five minutes—then you can go to the hospital." You should also head to the hospital if your amniotic sac ruptures, which is also known as your water breaking.

One exception to these guidelines: Women should visit their doctor ASAP if they lose the mucus plug before 37 weeks of pregnancy. This isn't necessarily cause for concern, especially if you're dealing with a subsequent pregnancy, but you should still have your doctor rule out complications like preterm labor.

Watching for Other Signs of Labor

Once you lose your mucus plug (if you notice it happening), you might want to look out for some other early signs of labor. "Other signs include 'lightening,' or the sensation that the baby has 'dropped,'" says Dr. Ward. "While this may result in more pressure in the pelvic region, breathing may be easier."

It's possible to also feel more cramping, back pain or even contractions. Changes in your activity level, including tiredness or nesting, may also occur, as well as a feeling of loose joints. "Your doctor may also let you know that your cervix has started to dilate or thin out," adds Dr. Ward.

Despite possible symptoms, there's usually no reason to worry when you lose your mucus plug near the end of pregnancy, especially when no other changes have occurred. "If you are full term—more than 37 weeks—there is probably no need to call your doctor unless you are bleeding heavily, contracting regularly, the mucus is particularly foul-smelling, or you are concerned that you may have broken your water," says Dr. Ward. But "although there is likely no need for concern, if you are ever uncertain as to whether or not to call your doctor, you should always call to be on the safe side."