Primiparity: a risk factor for brachial plexus injury in the presence of shoulder dystocia?

The objective of the study was to assess the risk factors associated with obstetric brachial plexus injury. It was a retrospective analysis over a 7-year period, of women whose labours were either complicated by shoulder dystocia or had neonates who sustained brachial plexus injury. The 133 women included were divided into two groups: (1) Non-brachial plexus injury (Non-BPI) group: 106 women with labours complicated by shoulder dystocia. (2) Brachial plexus injury (BPI) group: 27 women whose neonates sustained BPI. Comparison of ante-partum, intra-partum and post-partum factors was done. In the BPI group, there were significantly more nulliparous women, with more use of oxytocin. The neonatal variables were similar in both groups. Mean birth weight was more than 4 kg in both groups. In the presence of similar neonatal variables, brachial plexus injury is more likely to occur in neonates of primiparous women in the presence of shoulder dystocia, if labour is accelerated.