The color map reports the first principal right stretch for the baseline geometry evaluated with IUPs of (a) 25 weeks = 0.817 kPa, (b) 40 week = 2.33 kPa, and (c) contraction = 8.67 kPa. The percentage reports the volume fraction of the cervical internal os region above a 1.05 stretch. The membrane is removed for clarity. (For interpretation of the color in this figure legend, the reader is referred to the web version of this article.)