Purpose of study To study risk factors associated with obstetric brachial plexus injuries (OBPI) and to study outcomes of OBPI.

Methodology Retrospective audit study. All neonates with OBPI that were diagnosed in a tertiary maternity and neonatal unit over a 6 year period were identified and data about associated factors was collected from electronic health records and patients' case notes.

Results A total of 68 patients were identified between 2004 and 2009 averaging 2 per 1000 live births. 55% of mothers had body mass index (BMI) more than 25. In the general obstetric population, 40.5% of mothers had BMI >25 at booking. 85% of neonates with OBPI were over 4.5 kg. 51% of babies had shoulder dystocia. 95% of OBPIs were unilateral. 15% of OBPIs had associated injuries such as clavicle and humerus fractures. 7% of babies with OBPI were referred to a tertiary nerve injury unit. 69% of OBPIs resolved completely at 3 months of age, 22% between 3 and 12 months and 4% resolved after 12 months. 4% of the babies with OBPI needed ongoing follow-up after 12 months of age.

Conclusion OBPI is more likely to be associated when maternal BMI is more than 25 and birth weight of infants more than 4.5 kg. Complete resolution of OBPI within 3 months of age was observed in more than 2rd/3rd of the patients. The risk of sustaining OBPI should be individualised depending on antenatal risk factors. Most injuries resolve completely.