Cervical effacement or cervical ripening refers to a thinning of the cervix.

Background

Cervical effacement is a component of the Bishop score and can be expressed as a percentage. Prior to effacement, the cervix is like a long bottleneck, usually about four centimeters in length. Throughout

pregnancy Pregnancy is the time during which one or more offspring develops ( gestates) inside a woman's uterus (womb). A multiple pregnancy involves more than one offspring, such as with twins. Pregnancy usually occurs by sexual intercourse, but ...

, the cervix is tightly closed and protected by a plug of

mucus Mucus ( ) is a slippery aqueous secretion produced by, and covering, mucous membranes. It is typically produced from cells found in mucous glands, although it may also originate from mixed glands, which contain both serous and mucous cells. It ...

. When the cervix effaces, the mucus plug is loosened and passes out of the

vagina In mammals, the vagina is the elastic, muscular part of the female genital tract. In humans, it extends from the vestibule to the cervix. The outer vaginal opening is normally partly covered by a thin layer of mucosal tissue called the hymen ...

. The mucus may be tinged with

blood Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood in the cir ...

and the passage of the mucus plug is called

bloody show Bloody show is the passage of a small amount of blood or blood-tinged mucus through the vagina near the end of pregnancy. It is caused by the detachment of the cervical mucus plug that seals the cervix during pregnancy, and is one of the signs tha ...

(or simply "show"). As effacement takes place, the cervix then shortens, or effaces, pulling up into the uterus and becoming part of the lower uterine wall. Effacement may be measured in percentages, from zero percent (not effaced at all) to 100 percent, which indicates a paper-thin cervix. Results from a systematic review of the literature found no differences in

cesarean delivery Caesarean section, also known as C-section or caesarean delivery, is the surgical procedure by which one or more babies are delivered through an incision in the mother's abdomen, often performed because vaginal delivery would put the baby or mo ...

nor neonatal outcomes in women with low-risk pregnancies between inpatient or outpatient cervical ripening. Effacement is accompanied by

cervical dilation Cervical dilation (or cervical dilatation) is the opening of the cervix, the entrance to the uterus, during childbirth, miscarriage, induced abortion, or gynecological surgery. Cervical dilation may occur naturally, or may be induced surgically o ...

References

Childbirth Midwifery Obstetrics {{Human-repro-stub