Shoulder Dystocia — A Clinical Study of 56 Cases

Abstract

EDITORIAL COMMENT: This study confirms the well known fact that shoulder dystocia is more common with macrosomia, but also shows that the large baby of a diabetic is significantly more at risk than an equally large baby of a nondiabetic. There is much attention in the literature to the need to recognize the small for dates infant because of increased risk of perinatal mortality and morbidity. There is less emphasis on the need to recognize the large for dates baby although this can be equally important, especially in diabetics. Most authors have concluded that shoulder dystocia is usually unpredictable ‐ i.e. without clear indication for elective Caesarean section to avoid the risk; nobody would recommend elective section for all macrosomic babies since most are delivered uneventfully. However, past history of shoulder dystocia can justifv elective Caesarean section when the fetus appears large on clinical evidence. Delay in the second stage of labour and slow descent of the head in an obese multipara should warn the clinician that Caesarean section rather than mid‐forceps delivery is the best decision, especially when the fetus seems large. Unfortunately clinical judgement in these cases is often not helped by ultrasonographic evidence of birth‐weight, in this editor's experience. The obese multipara labouring ineffectively should always be taken as a warning that the baby may be larger than expected, and that Caesarean section, not enhancement of labour with oxytocin, is the proper management. Since there is often no time to summon aid, all accouchers should have a plan of how to manage shoulder dystocia ‐ the authors provide most details and it shoulder be noted that all their patients were delivered in the lithotomy position ‐ the dorsal position does not allow downwards traction to release the anterior shoulder, and time is short when the complication has occurred. (See previous comment on Shoulder Dystocia, Aust NZ J Obstet Gynaecol 1988; 28: 107) Summary: A retrospective analysis of 17,127 singleton vaginal deliveries revealed 56 cases of shoulder dystocia giving an incidence of 0.3%. Although an increasing incidence of shoulder dystocia was noted as the infant birth‐weight increased, 41% of shoulder dystocia occurred in infants of average birth‐weight (2,500–3,999g). Diabetes mellitus, postmaturity, maternal weight above 90 kg were each factors associated with a large sized infant which should signal the possible occurrence of shoulder dystocia. In the present series shoulder dystocia occurred in 2.7% of all infants weighing 4,000 g or more. Diabetic women experienced shoulder dystocia more often than non‐diabetics. In the diabetics 15.7% of neonates of birth‐weight 4,000 g and above sustained shoulder dystocia compared to 1.6% in the nondiabetic patients. Immediate neonatal injury was apparent in 43% of infants with shoulder dystocia, Erb palsy being the commonest injury. The perinatal mortality rate in the series was 54/1,000 deliveries. There was no maternal death. To avoid the potentially lethal and dangerous complications of shoulder dystocia, all clinical and technological methods available should be utilized to detect the excessive sized infants so that abdominal delivery may be performed before it is too late.