Increased incidence of shoulder dystocia but a declining incidence of obstetric brachial plexus palsy in vaginally delivered infants.

INTRODUCTION: Obstetric brachial plexus palsy (OBPP) is a serious form of neonatal morbidity. The primary aim of this population-based registry study was to examine temporal trends, 1997-2019, of OBPP in infants delivered vaginally in a cephalic presentation. The secondary aim was to examine temporal changes in the incidence of associated risk factors. MATERIAL AND METHODS: This was a population-based registry study including singleton, cephalic, vaginally delivered infants, 1997-2019, in Sweden. To compare changes in the incidence rates of OBPP and associated risk factors over time, univariate logistic regression was used and odds ratios (OR) with 95% confidence intervals (CI) were calculated. RESULTS: The incidence of OBPP in infants delivered vaginally in a cephalic presentation decreased from 3.1 per 1000 births in 1997 to 1.0 per 1000 births in 2019 (OR 0.31, 95% CI 0.24-0.40). Conversely, the incidence of shoulder dystocia increased from 2.0 per 1000 in 1997 to 3.3 per 1000 in 2019 (OR 1.64, 95% CI 1.34-2.01). Over time, the proportion of women with body mass index of 30 kg/m2 or greater increased (14.5% in 2019 compared with 8.0% in year 1997, OR 1.96, 95% CI 1.89-2.03), more women had induction of labor (20.5% in 2019 compared with 8.6% in 1997, OR 2.74, 95% CI 2.66-2.83) and epidural analgesia (41.2% in 2019 compared with 29.0% in 1997, OR 1.72, 95% CI 1.68-1.75). In contrast, there was a decrease in the rate of operative vaginal delivery (6.0% in 2019, compared with 8.1% in 1997, OR 0.72, 95% CI 0.69, 0.75) and in the proportion of infants with a birthweight greater than 4500 g (2.7% in 2019 compared with 3.8% in 1997, OR 0.70, 95% CI 0.66-0.74). The decline in the incidence of these two risk factors explained only a small fraction of the overall decrease in OBPP between 1997-2002 and 2015-219. CONCLUSIONS: The incidence of OBPP in vaginally delivered infants in a cephalic presentation at birth decreased during the period 1997-2019 despite an increase in important risk factors including shoulder dystocia.

Long-term follow-up of children with obstetric brachial plexus palsy I: functional aspects.

The aims of this study were to describe the development of sequelae in obstetric brachial plexus palsy (OBPP) and to identify possible differences in functional outcome from 5 years of age to follow-up, 2 to 15 years later. A cohort of 70 participants (35 males, 35 females; age range 7-20y, mean 13y 6mo [SD 4y 3mo], median 13y) with OBPP of varying degrees of severity were monitored. Differences in status between 5 years of age and follow-up were studied. Active joint motion in the shoulder and hand function, especially grip strength, generally remained unchanged or improved, whereas a slight but significant deterioration occurred in elbow function. Shoulder surgery resulted in considerable improvement of shoulder function. Participants with nerve reconstruction had a similar profile of change as the non-operated group. It was concluded that ongoing follow-up of children with OBPP, beyond the preschool years, is required due to decreases in elbow function, a commonly occurring restriction in external rotation of the shoulder, together with individual variations in long-term outcomes. In a related article (part II: neurophysiological aspects) long-term neurophysiological and sensory aspects of OBPP are reported.

Long-term follow-up of children with obstetric brachial plexus palsy II: neurophysiological aspects.

The aim of this study was to examine long-term neurophysiological outcomes and sensory function in patients with obstetric brachial plexus palsy (OBPP). The same 70 children/adolescents examined in part I: functional aspects (35 males, 35 females; age range 7-20y, mean 13y 6mo [SD 4y 3mo], median 13y) were examined with neurophysiological methods at 3 to 7 months and at 7 to 20 years of age. Thirteen of the 70 participants underwent nerve reconstruction before 1 year of age. Electromyography (EMG) was performed on deltoid and first interossei muscles; Quantitative Sensory Test was used for C6 and C8 dermatomes. Tests for functional sensibility and 2-point discrimination for C6 and C8 were performed. This study shows that considerable EMG changes can be observed in OBBP, even in those fully recovered. EMG changes in the deltoid were shown to deteriorate over time, and sensibility is considerably less affected than motor function.