Study population
A total of 208 nulliparous women were recruited into our study. We
excluded 27 women who decided elective cesarean delivery for the
following reasons: changed their
minds and rejected attempting to a vaginal delivery after an MRI
examination (n = 25), pre-eclampsia (n = 2). Of the eligible 181 women,
twenty-nine were excluded for immediate urgency situation of fetal
compromise, one was excluded for incomplete data and one withdrew her
consent (Figure S1). Table 1 illustrates the baseline clinical
characteristics, MRI measurements for the study population. Of the
remaining 150 women for analysis, the mean age was 30 years and the mean
height was 158 cm. Sixty-two women required cesarean delivery (41%),
while eighty-eight women (59%) underwent vaginal delivery: among these,
12 women (8%) were performed assisted
operative deliveries using forceps
and 76 (51%) achieved spontaneous vaginal delivery.