Prostaglandins are sufficient to promote cervical ripening and are necessary for LPS-induced premature cervical ripening. A, Biomechanical testing of cervices obtained at gestational day 15 (d15), day 18 (d18), day 15 mifepristone (MFP), day 15 6-hour IU-LPS (IU LPS), day 15 12-hour IP-LPS (IP LPS), day 15 12-hour IP-LPS + SC-236, and day 15 6-hour misoprostol (Miso) [n = 17 (d15); n = 6 (d18); n = 5 (MFP); n = 9 (IU LPS); n = 3 (IP LPS); n = 5 (IP LPS+SC-236); and n = 5 (d15 misoprostol)]. Groups within a single bracket are not significantly different from each other, whereas each bracketed group is significantly different (P ≤ .05) from every other bracketed group. B, Table showing coefficient estimates (mean ± SEM) for all groups in panel A. *, Rows with the same numeric indicator are not judged statistically different.