RT Journal Article SR Electronic T1 Intrapartum ultrasonography may improve operative vaginal delivery outcomes in Canada JF Canadian Medical Association Journal JO CMAJ FD Canadian Medical Association SP E261 OP E261 DO 10.1503/cmaj.81136 VO 194 IS 7 A1 Kiely, Daniel J. YR 2022 UL http://www.cmaj.ca/content/194/7/E261.abstract