Cervical ripening is the hormonal softening of the cervix that usually occurs prior to the onset of labor contractions. Earlier in pregnancy and in non-pregnant women, the cervix is tight, separating the uterus from the vagina.
The cervix needs to soften (ripen), thin (efface), and open (dilate) in order for the fetus to pass through it during childbirth. If cervical ripening does not occur naturally once a pregnancy has reached term, it may need to be induced by a health care provider.
FertilitySmarts explains Cervical Ripening
During pregnancy, the cervix remains closed to protect the fetus while it’s developing. The cervix is mainly composed of collagen, allowing it to remain firm during pregnancy and resist the pressure created by the growing uterus and fetus. As a pregnancy reaches term, hormones are released into the woman’s body that causes the cervix to begin ripening. Ripening occurs when the cervix receives a higher content of water and more blood flow, causing it to become softer. These changes in the cervix allow it to stretch and thin in response to labor contractions. The stretching and thinning of the cervix enables the fetus to pass from the uterus into the vagina during childbirth.
The readiness of the cervix for labor is measured by health care providers using something called the Bishop score. With this system of measurement, the condition of the cervix is given a rating of 0-13. A Bishop score of less than 6 means that the cervix may not be ripe enough for labor.
If the cervix does not ripen enough on its own, a health care provider may need to induce it. This can be accomplished by administering drugs, called prostaglandins, stripping the membranes (separating the amniotic sac from the uterine wall), inserting laminaria (a substance that absorbs water), or using a balloon catheter to encourage opening the cervix.