MR pelvimetry: prognosis for successful vaginal delivery in patients with suspected fetopelvic disproportion or breech presentation at term

Purpose The purpose of this study was to correlate MR pelvimetric pelvic inlet measurements with mode of delivery and neonatal outcome in patients with suspected fetopelvic disproportion or breech presentation. Methods For this retrospective monocentric study, 237 consecutive MR pelvimetry reports ( 1999-2016) of pregnant women due to either suspected fetopelvic disproportion, pelvic deformation after trauma, or persistent breech presentation were retrieved from the radiologic database and matched with corresponding information from the obstetric database. Results Of 223 included women, 95 ( 42.6%) underwent planned cesarean section ( pCS) and 128 ( 57.4%) underwent a trial of vaginal labour ( TOL), of whom 93 ( 72.7%) delivered vaginally. Vaginal delivery was successful in 45 out of 64 ( 70.3%) cephalic cases and in 48 out of 64 ( 75.0%) breech cases. We found statistically significant differences in conjugata vera obstetrica ( CV) and diameter transversalis ( DT) between the groups TOL and pCS ( CV: 12.5 +/- 1.0 vs 12.1 +/- 1.2 cm, p value 0.001; DT: 13.3 +/- 0.9 vs 12.7 +/- 0.9 cm, p value <0.001, respectively). However, there was no significant difference between successful VD and cesarean section after TOL (CV: 12.5 +/- 0.9 vs 12.3 +/- 1.1 cm, p value 0.194; DT: 13.4 +/- 0.9 vs 13.2 +/- 0.9 cm, p value 0.358, respectively). Conclusions In our cohort, MR pelvimetry was a useful tool for prepartal assessment of the female pelvis in the selection of TOL candidates. Yet, it does not seem to yield additional predictive value for women with a previous vaginal delivery.