Impact of shoulder dystocia, stratified by type of manoeuvre, on severe neonatal outcome and maternal morbidity

Abstract

Background: Shoulder dystocia is an uncommon and unpredictable obstetric emergency. It is associated with significant neonatal, maternal and medico-legal consequences.

Aim: To ascertain the impact shoulder dystocia has on severe neonatal and maternal outcomes specific to the type of manoeuvre.

Materials and methods: This was a retrospective study of 48 021 term singleton vaginal deliveries the Mater Mothers' Hospital in Brisbane between 2007 and 2015. Maternal and neonatal outcomes were compared between deliveries complicated by shoulder dystocia and those uncomplicated.

Results: Deliveries complicated by shoulder dystocia are associated with low Apgar scores (≤3) at five minutes (odds ratio (OR) 5.25, 95% CI 3.23-8.56, P < 0.001), acidosis (OR 3.10, 95% CI 2.76-3.50, P < 0.001), postpartum haemorrhage (OR 2.28, 95% CI 1.90-2.75, P < 0.001) and perineal trauma (OR 1.92, 95% CI 1.54-2.39, P < 0.001). Compared to McRoberts' manoeuvre and suprapubic pressure alone, the odds of serious neonatal outcome are increased with internal rotational manoeuvres (OR 3.82, 95% CI 2.54-5.74, P < 0.001) and delivery of the posterior arm (OR 4.49, 95% CI 3.54-5.69, P < 0.001). The OR of maternal injury is 2.07 (95% CI 1.77-2.45, P < 0.001), 2.26 (95% CI 1.21-4.21, P < 0.001) and 2.29 (95% CI 1.58-3.32, P < 0.001) with McRoberts'/suprapubic pressure, internal rotation and posterior arm delivery, respectively. Brachial plexus injuries and fractures complicate 1.4 and 0.9% of deliveries, with the risk of injury increasing when greater than one manoeuvre is required.

Conclusion: The risk of neonatal and maternal trauma is strongly associated with the number and types of manoeuvres. Given the associated implications, adequate antenatal counselling, simulation training and enhanced labour surveillance are essential.

Keywords: McRoberts' manoeuvre; birth injury; brachial plexus injury; shoulder dystocia.