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. 2023 Jan;102(1):76-81.
doi: 10.1111/aogs.14481. Epub 2022 Nov 8.

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

Margareta Mollberg  1 , Linnea V Ladfors  2 , Christina Strömbeck  3 , Helen Elden  1 , Lars Ladfors  4
Affiliations

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

Margareta Mollberg et al. Acta Obstet Gynecol Scand. 2023 Jan.

Abstract

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.

Keywords: delivery, obstetric; logistic models; mode of delivery; neonatal brachial plexus palsy; obstetric brachial plexus palsy; risk factors; shoulder dystocia; simulation; vacuum extraction, obstetrical.

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Conflict of interest statement

The authors have stated explicitly that there are no conflicts of interest in connection with this article.

Figures

FIGURE 1
FIGURE 1
Temporal trends in incidence (per 1000 deliveries) of obstetric brachial plexus palsy (OBPP) and shoulder dystocia in vaginal deliveries with singleton infants in cephalic presentation, in Sweden, 1997–2019 (n = 1 877 116).
FIGURE 2
FIGURE 2
Temporal trends in the incidences (%) of risk factors for obstetric brachial plexus palsy in vaginal, singleton, cephalic deliveries, 1997–2019 in Sweden. BMI, body mass index.
See this image and copyright information in PMC

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