title: Predictive factors for the success of McRoberts' manoeuvre and suprapubic pressure in relieving shoulder dystocia: a cross-sectional study.
abstract: McRoberts' and suprapubic pressure are often recommended as the initial choices of manoeuvres to manage shoulder dystocia, as they are believed to be less invasive compared to other manoeuvres. However, their success rates range from 23 to 40 %. This study aims to investigate the predictive factors for the success of McRoberts' manoeuvre with or without suprapubic pressure (M+/-S).
  
  
  
  All cases of shoulder dystocia in a tertiary hospital in South East Asia were recruited from 1995 to 2009. Subjects were analysed according to either 'success' or 'failure' of M+/-S. Maternal and fetal antenatal and intrapartum factors were compared by univariate and multivariate analysis.
  
  
  
  Among 198 cases of shoulder dystocia, M+/-S as the primary manoeuvre was successful in 25.8 %. The other 74.2 % needed either rotational or posterior arm manoeuvres or combination of manoeuvres. Instrumental delivery was the single most significant factor associated with an increased risk of failed M+/-S on logistic regression (p < 0.001, OR 4.88, 95 % CI 2.05-11.60). The success rate of M+/-S was only 15.0 % if shoulder dystocia occurred after instrumental delivery but was 47.7 % after spontaneous vaginal delivery.
  
  
  
  When shoulder dystocia occurs after instrumental vaginal delivery, the chance of failure of M+/-S is 85 %, which is 4.7 times higher than that after spontaneous vaginal delivery. Hence all operators performing instrumental delivery should be proficient in performing all manoeuvres to relieve shoulder dystocia when M+/-S cannot do so.
authors: Department of Obstetrics and Gynaecology, The Chinese University of Hong Kong, Prince of Wales Hospital, 30-32 Ngan Shing Street, Shatin, Hong Kong SAR, China.
authors: Zara Lin Zau
authors: ZL
authors: Lok
authors: Department of Obstetrics and Gynaecology, The Chinese University of Hong Kong, Prince of Wales Hospital, 30-32 Ngan Shing Street, Shatin, Hong Kong SAR, China.
authors: Yvonne Kwun Yue
authors: YK
authors: Cheng
authors: Department of Obstetrics and Gynaecology, The Chinese University of Hong Kong, Prince of Wales Hospital, 30-32 Ngan Shing Street, Shatin, Hong Kong SAR, China. tyleung@cuhk.edu.hk.
authors: Tak Yeung
authors: TY
authors: Leung
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D036861:Delivery, Obstetric / Q000295:instrumentation / Q000379:methods*; D004420:Dystocia / Q000628:therapy*; D005260:Female; D006801:Humans; D015999:Multivariate Analysis; D011247:Pregnancy; D011312:Pressure; D012189:Retrospective Studies; D012782:Shoulder; D016896:Treatment Outcome
keywords: Instrumental delivery; McRoberts’ manoeuvre; Shoulder dystocia; Suprapubic pressure; Vacuum extraction