What You Need To Know About Cervical Effacement

Talk about the human birthing process and the stages of labor usually includes statements about how the cervix has dilated by so many inches or centimeters after minutes or hours of active labor.

But any discussion of cervical dilation should include cervical effacement.

What is cervical effacement?

Cervical effacement is one of the processes by which the cervix prepares itself for delivery, according to the American Pregnancy Association (APA). Here, the surface of the cervix thins. This is different from cervical ripening, when the cervix softens.

This process of effacement occurs as the child begins to drop from the womb in preparation for birth.

The cervix can efface before dilation. Many factors help determine which part of cervical change occurs and when.

The only way cervical effacement may be confirmed is through an examination by a physician.

Effacement and dilation are two different things, said Allison Hill, M.D., an OB-GYN based in Los Angeles.

During effacement, the width of the cervix's dilation is between 0 cm and 10 cm. Effacement is measured in percentages ranging from 0 percent, wherein the cervix is still at its normal length, to 100 percent, where it has contracted to its shortest to allow passage of the infant out of the womb.

"It's important to understand that effacement has to be at 100 percent and cervical dilation at 10 cm for a vaginal delivery to commence," Hill said.

Together with dilation, effacement works to loosen the mucus plug, or the mucus that forms in the birth canal to prevent bacteria from entering.

How is effacement determined?

Gynecologists and obstetricians gauge the level of effacement by checking the cervix with gloved fingers. These exams may be done in the 36th or 37th week of pregnancy if the patient is having contractions or other symptoms and labor needs to be ruled out. It may be performed if a patient requests an exam or is being scheduled for induction.

Effacement does not mean a pregnant person is in labor.

However, even if the cervix is fully effaced and dilated, doctors cannot give an accurate assessment of how soon the baby will be born. A woman may be fully effaced well before the cervix has completely dilated, but it isn't typical.

How do you know that you have effaced?

Most women are never aware that they are already undergoing cervical effacement. Many are only aware of dilation.

As a guide, here are several signs that indicate the pregnant parent is already undergoing cervical effacement:

• Experiencing Braxton-Hicks contractions
• Loss of the mucus plug
• Sensation akin to feeling the baby about to drop or fall out of one's womb
• Increase in vaginal secretions

Keep in mind, however, that not all pregnant women will experience these symptoms.

There is no way for an individual patient to measure the extent of their effacement, according to Randle Umeh, M.D., an OB-GYN at Women's Care of El Paso in Texas. The only way cervical effacement may be confirmed is through an examination by a physician.

What are the possible complications of cervical effacement?

Like all natural physiological processes, there is always the risk of complications as the body undergoes cervical effacement. Mostly, these are related to either early or late effacement.

In the case of early effacement, the patient is suffering from a condition known as insufficient cervix, Umeh said. Here, the cervix begins to thin well before the pregnancy has come to full term, with many cases occurring within the second trimester.

Early effacement can lead to the following issues:

• Premature labor, often as early as the end of the second trimester
• Premature breaking of the amniotic sac
• Miscarriage or premature delivery

Factors that can contribute to early effacement include the following:

• Multiple babies, such as twins or triplets
• Biologically immature cervix
• History of miscarriages
• Previous abortions conducted within the first and second trimesters
• Torn cervix that did not heal properly after birth
• Other surgical or invasive diagnostic procedures performed on the cervix

On the other hand, Hill explained that the cervix of someone undergoing late effacement remains long and thick even as the pregnancy draws to a close. This results in delayed labor, and the pregnancy may go on for 40 to 42 weeks.

To alleviate late effacement, a physician may suggest any of the following treatments:

• Prostaglandin injections to soften or ripen the cervix
• Introduction of laminaria, or tools that expand in water, to stimulate effacement and dilation
• Use of a catheter-inserted balloon to put pressure on the cervix to induce cervical effacement and dilation

When should you consult your physician?

Effacement is completely natural. However, certain symptoms can indicate a complication, such as heavy vaginal bleeding, painful and constant labor contractions, feeling no movement from your baby or your water breaking.

If you have questions or concerns about your pregnancy, labor or delivery, speak with your doctor.