General guidelines for cervical dilation: During pregnancy, the os (opening) of the cervix is blocked by a thick plug of mucus to prevent bacteria from entering the uterus.
ACOG's findings conclude that the collagen softening properties of misoprostol could be absorbed through the cervix and vaginal vault up into the low transverse scar of a typical caesarean section, and significantly increase the risk of uterine rupture.
[3][obsolete source] Prostaglandins are also present in human semen, and sexual intercourse is commonly recommended for promoting the onset of labor, although the limited data available makes the effectiveness of this method uncertain.
Henci Goer, in her comprehensive book, The Thinking Woman's Guide to a Better Birth, details how this practice was researched in two separate studies of 100 and 200 women in the mid nineteen-eighties.
Other products include osmotic dilators, such as laminaria stick (made of dried seaweed) or synthetic hygroscopic materials, which expand when placed in a moist environment.
[2] Results from 2021 systematic reviews of the literature found no differences in caesarean delivery, neonatal, nor maternal outcomes between inpatient or outpatient cervical ripening.
[6][7] In treatment of spontaneous or induced abortion, preparation (softening and dilating) of the cervix allows the cannulae vacuum aspiration to pass more easily into the uterus, which may make the procedure shorter in duration, more comfortable for the patient, and easier to perform.
In hysteroscopy, the diameter of the hysteroscope is generally too large to conveniently pass the cervix directly, thereby necessitating cervical dilation to be performed prior to insertion.