Furthermore, failed IOL must be differentiated from failure to progress in labour and from cephalopelvic disproportion
For example, a patient lacking significant risk factors for dystocia having a history of a vaginal delivery followed by a cesarean for breech or a woman who has already had one or more vaginal deliveries after cesarean should not trigger the same set of mandates/guidelines as a short, obese, 36-year-old secundigravida whose initial cesarean was for an arrest disorder consistent with cephalopelvic disproportion
This may help in predicting cephalopelvic disproportion
when labour progress is poor, (1) or give early warning of possible shoulder dystocia.
Up to 77 percent of women for whom the indication for cesarean delivery was a nonprogressive labor (sometimes diagnosed as cephalopelvic disproportion
or CPD) and who tried labor again, had a VBAC for a subsequent birth.