Shoulder dystocia: risk factors and maternal and perinatal outcome

Shoulder dystocia (S.D.) is an obstetric emergency which may be catastrophic for both mother and baby. The aims of this study were to determine the incidence of S.D., the maternal and perinatal outcome, and which risk factors were important. This was a retrospective review of all cases of S.D. during 1997 and 1998. Controls were selected as the next vaginal delivery following the S.D. case, matched for age, parity and gestation at delivery. Risk factors were compared between the two groups. There were 54 cases of S.D. over the study period, an incidence of 0.57% of 9541 vaginal deliveries. There were significant differences between cases and controls in birth weight, active phase of 1st stage of labour, 2nd stage of labour, episiotomy rate, third-degree tear rate, admission to SCBU and trauma to the baby at delivery. There were two infants with fractured clavicle and two with Erb's palsy.