Does body mass index influence the degree of pelvic tilt produced by a Crawford wedge?

• Published in: International journal of obstetric anesthesia 2013-04, Vol.22 (2), p.129-132
• Main Authors: Harvey, N.L, Hodgson, R.L, Kinsella, S.M
• Format: Article
• Language: English
• Subjects: Adult; Anesthesia & Perioperative Care; Anesthesia, Obstetrical; Body Mass Index; Caesarean section; Cesarean Section - methods; Crawford wedge; Female; Humans; Obesity; Obstetrics and Gynecology; Patient Positioning; Pelvic tilt; Pelvis - anatomy & histology; Pregnancy
• ISSN: 0959-289X; 1532-3374
• DOI: 10.1016/j.ijoa.2012.11.002

Abstract Background A pelvic tilt of 15° is standard practice when positioning a woman for caesarean section, and is commonly produced by tilting the operating table or placing a wedge under the right hip. This study investigated whether body mass index affects the degree of pelvic tilt produced when a wedge is used. Methods Women undergoing category 3 and 4 caesarean sections were stratified into three groups according to their body mass index at antenatal booking: ⩽25 kg/m2 , 25.1–35 kg/m2 and >35 kg/m2 . Twenty women were recruited into each group. Lateral tilt at caesarean section was provided with a Crawford wedge under the right hip and the degree of pelvic tilt was measured using a protractor device. Results The median [range] pelvic tilt angle for the groups in order of ascending body mass index were 15° [12–22°], 19° [11–29°] and 17° [2–28°]. There was a significant increase in the variability of pelvic tilt with increasing body mass index ( P = 0.001). The proportion of patients with pelvic tilt 35 kg/m2 , respectively. Conclusion Variability in pelvic tilt increased with body mass index and was greatest with a booking body mass index >35 kg/m2.