CIA Pelvimetry Score as a Predictor of Mode of Delivery [ID 1266]

INTRODUCTION: Classic clinical pelvimetry to assess the adequacy of the pelvis for vaginal birth is an important skill that has been lost to many obstetric care providers. This study evaluates a novel system for simplified clinical pelvimetry as a predictor of vaginal delivery. METHODS: In this prospective cohort study, providers conducted the coccyx, ischial spines, and pubic arch (CIA) pelvimetry scoring during routine cervical examinations on study participants. Patient-informed consent was obtained. The CIA score was assessed for each participant with 1 being distant, 3 being prominent, and 2 being not 1 or 3. A cumulative score ranging from 3 to 9 was determined for each participant. Participants included pregnant people undergoing induction of labor at term. The CIA scores were compared with mode of delivery: spontaneous vaginal, vacuum-assisted, forceps-assisted, or cesarean. RESULTS: One hundred thirty-eight participants with CIA scores and known mode of delivery were included in the study: CIA score of 3, 32/37 (86.5%) vaginal delivery; CIA score of 4, 23/33 (69.7%) vaginal delivery; CIA score of 5, 18/32 (56.3%) vaginal delivery; CIA score of 6, 22/29 (75.9%) vaginal delivery; CIA score of 7, 4/6 (66.7%) vaginal delivery; CIA score of 9, 0/1 (0%) vaginal delivery. CONCLUSIONS/IMPLICATIONS: The CIA pelvimetry score is a novel means of assessing the pelvis that is easy to perform and offers acceptable interprovider reproducibility. These data suggest it may help predict vaginal delivery, but larger studies are needed.