Interventions to decrease complications after shoulder dystocia: a systematic review and Bayesian meta-analysis.

OBJECTIVE: This study aimed to evaluate the outcomes associated with the implementation of simulation exercises to reduce the sequela of shoulder dystocia. DATA SOURCES: Electronic databases (Ovid MEDLINE, Embase, the Cumulative Index to Nursing and Allied Health Literature database, and Scopus) were initially queried in June 2020 and updated in November 2020. The following 3 concepts were introduced and refined using the controlled vocabulary of the database: vaginal birth, shoulder dystocia, and simulation training. There were no limitations to the year of publication as part of the search strategy. STUDY ELIGIBILITY CRITERIA: We included all studies that reported on the frequency of shoulder dystocia and the associated complications before and after the implementation of interventional exercises to improve outcomes. METHODS: Two authors independently assessed the abstracts and full-text articles of all studies for eligibility and evaluated the quality of the included studies using the Newcastle-Ottawa Scale. Any inconsistencies related to study evaluation or data extraction were resolved by a third author. The coprimary outcomes of this systematic review and meta-analysis were neonatal brachial plexus palsy diagnosed following deliveries complicated by shoulder dystocia and persistence of brachial palsy at 12 months or later. The secondary outcomes were the frequency of shoulder dystocia and cesarean delivery. Study effects were combined using a Bayesian meta-analysis and were reported as risk ratios and 95% credible intervals (Crs). RESULTS: Of the 372 articles reviewed, 16 publications, which included 428,552 deliveries with 217,713 (50.8%) deliveries during the preintervention and 210,839 (49.2%) deliveries during the postinterventional period, were included in the meta-analysis. The incidence of neonatal brachial plexus palsy after shoulder dystocia decreased from 12.1% to 5.7% (risk ratio, 0.37; 95% Cr, 0.26-0.57; probability of reduction 100%). The overall proportion of neonatal brachial plexus palsy decreased, but with less precision, from 0.3% to 0.1% (risk ratio, 0.53; 95% Cr, 0.21-1.26; probability of reduction 94%). Two studies followed newborns with brachial plexus palsy for at least 12 months. One study that reported on persistent neonatal brachial plexus palsy at 12 months among 1148 shoulder dystocia cases noted a reduction in persistent neonatal brachial plexus palsy from 1.9% to 0.2% of shoulder dystocia cases (risk ratio, 0.13; 95% confidence interval, 0.04-0.49). In contrast, the study that reported on persistent neonatal brachial plexus palsy at 12 months for all deliveries noted that it did not change significantly, namely from 0.3 to 0.2 per 1000 births (risk ratio, 0.77; 95% confidence interval, 0.31-1.90). Following the implementation of shoulder dystocia interventional exercises, the diagnosis of shoulder dystocia increased significantly from 1.2% to 1.7% of vaginal deliveries (risk ratio, 1.39; 95% Cr, 1.19-1.65; probability of increase 100%). Compared with the preimplementation period, the cesarean delivery rate increased postimplementation from 21.2% to 25.9% (risk ratio, 1.22; 95% Cr, 0.93-1.59; probability of increase 93%). We created an online tool (https://ccrebm-bell.shinyapps.io/sdmeta/) that permits calculation of the absolute risk reduction and absolute risk increase attributable to the intervention vis-à-vis the incidence of shoulder dystocia, neonatal brachial plexus palsy, and cesarean deliveries. CONCLUSION: Introduction of shoulder dystocia interventional exercises decreased the rate of neonatal brachial plexus palsy per shoulder dystocia case; the data on persistence of neonatal brachial plexus palsy beyond 12 months is limited and contradictory. Implementation of the interventions was associated with an increase in the diagnosis of shoulder dystocia and rate of cesarean deliveries.

Axillary traction: An effective method of resolving shoulder dystocia.

BACKGROUND: At Counties Manukau Health in Auckland, New Zealand, axillary traction is being used when an internal manoeuvre is required for resolution of shoulder dystocia. AIMS: This study presents the outcomes for mother and baby from use of axillary traction and other internal manoeuvres. MATERIALS AND METHODS: Retrospective review of the clinical records of mother and baby for all labours complicated by shoulder dystocia was carried out for an eight-year period. Maternal and neonatal information were compared for the three cohorts of the first internal manoeuvre documented: axillary traction, posterior arm delivery and rotational manoeuvres. RESULTS: There were 226 women who required the use of internal manoeuvres with no significant differences in age, body mass index, parity, ethnicity, diabetes incidence, induction and augmentation of labour rates, length of the first stage and birth weight between the cohorts. Axillary traction was the first internal manoeuvre used for 119 (52.7%) with a success rate of 95.8%. Posterior arm delivery was used first for 49 (21.7%) women with a success rate of 85.7%. Rotational manoeuvres were used first for 58 (25.7%) women with a statistically inferior success rate of 48.3%. There was no significant difference in the maternal and neonatal complication rates between the cohorts. CONCLUSION: Axillary traction has been utilised as the first internal manoeuvre for a large number of women with a higher success rate than other internal manoeuvres without any increase in maternal or neonatal morbidity. It is recommended that this be the first internal manoeuvre attempted when shoulder dystocia occurs.

Risk of recurrent shoulder dystocia: are we any closer to prediction?

Objective: To determine the incidence and risk factors for recurrent shoulder dystocia in women. Methods: We searched Medline, Pubmed, Embase, and CINAHL for relevant articles in English and French from 1980 to February 2018 that described risks of recurrent shoulder dystocia undergoing a trial of labour in subsequent pregnancies. A total of 684 articles were found, of which 13 were included as they met criteria. We extracted data on study characteristics, incidence of recurrent shoulder dystocia, degree of neonatal injury, and presence of known risk factors. Results: There was a wide variation in the incidence of shoulder dystocia in subsequent pregnancies from 1-25%. The largest cohort reported a risk of 13.5%. The most important risk factor for recurrent shoulder dystocia is an increase in birthweight in the subsequent pregnancy compared to the index pregnancy (OR 7-12). Prolonged second stage, instrumental delivery, maternal diabetes, increased maternal BMI, and severe neonatal morbidity in the index pregnancy were also associated with an increased risk of recurrent shoulder dystocia. However, many of these risk factors were present in women who did not have a recurrent shoulder dystocia. In addition, women with recurrent shoulder dystocia rarely had identifiable risk factors, other than the history of previous shoulder dystocia. Sample sizes were low as most studies are single centre, retrospective cohorts with low rates of subsequent pregnancy and vaginal birth as many women may have elected to have a caesarean section in subsequent pregnancies or were lost to follow up. There was a high rate of reporting bias and heterogeneity, prohibiting formal meta-analyses. Conclusion: Recurrent shoulder dystocia is an unpredictable obstetric complication with potentially devastating consequences. Individual assessment and thorough counselling should be offered to women contemplating a subsequent planned vaginal birth with specific attention paid to those women where the estimated birthweight is >4000 g or greater than in the index pregnancy.