Impact of Introducing PROMPT on Permanent Brachial Plexus Injury and Tears III°/IV° in Shoulder Dystocia: The Hanover Cohort Study

Objective To test the hypothesis that PROMPT reduces permanent brachial plexus palsy and perineal tears. Design A prospective/retrospective cohort study. Setting. Hanover Medical School, Germany. Population/Sample. A self-selected population. Methods The training period is from November 9th, 2017, until December 31st, 2019; control: January 1st, 2004, until November 8th, 2017. Main Outcome Measures. Shoulder dystocia, nonpermanent and permanent brachial plexus injuries (BPIs), perineal tears III°/IV°, manual manoeuvres, and asphyxia. Results There was a total of 22,640 births, and shoulder dystocia increased from 48/18,031 (0.27%) to 23/4,609 (0.50%) ((p=0.017), OR: 1.88, 95% CI: (1.14; 3.09)), whereas BPIs decreased from 7/48 (14.6%) to 1/23 (4.3%) (p=0.261). There was 1/7 (14.2%) of permanent BPI before and 0/1 (0%) case after. Perinatal asphyxia increased from 3/48 (6.3%) to 4/23 (17.4%) (p=0.23). However, adverse outcomes after one year were zero. McRoberts' manoeuvre increased from 37/48 (77.1%) to 23/23 (100%) ((p=0.013), OR: 1.62, 95% CI: (1.33; 1.98)), and internal rotation manoeuvres and manual extraction of the posterior arm from 6/48 (12.5%) to 5/23 (21.7%) (p=0.319). Episiotomies decreased from 5,267/18,031 (29.2%) to 836/4,609 (18.1%) ((p < 0.001), OR: 0.54, 95% CI: (0.49, 0.58)), whereas perineal tears III°/IV° associated with shoulder dystocia increased from 1/48 (2.1%) to 1/23 (4.8%) (p=0.546). Vaginal operative deliveries remained constant (6.5% vs. 7%). Conclusions PROMPT significantly improves the management of shoulder dystocia and decreases permanent brachial plexus injuries but not perineal tears III°/IV°.


PROMPT (Practical Obstetric Multiprofessional Training
) is a trial-based multiprofessional training concept of rare obstetric complications focusing on teamwork and communication, set up in Bristol, UK, in 2000.Te efectiveness of the training has been demonstrated in many trials (https://www.promptnz.org/evidence-of-efectiveness).In 2017, PROMPT was introduced at the Hannover Medical School in Germany.
Shoulder dystocia is a rare but severe obstetrical emergency, leading to severe complications for the newborn, such as brachial plexus injury (BPI), brain damage due to hypoxia, and fetal death.It may also seriously harm the mother.Te actual incidence of shoulder dystocia is thought to be between 2-3% worldwide [1].Risk factors have been identifed, such as fetal macrosomia, type I diabetes or gestational diabetes, shoulder dystocia in a previous pregnancy, labour induction, epidural anaesthesia, vaginal operative delivery, and very short and prolonged second stage of labour [2].However, these risk factors have a low predictive value, and many cases of shoulder dystocia are not associated with any of these parameters.Brachial plexus injury is the most common complication of shoulder dystocia, with an incidence of 0.5-4.0 per 1000 cases [3].It has been shown in many studies that the implementation of training can reduce the incidence of BPIs [4].A retrospective cohort study by Draycott et al. found that practical training (PROMPT) led to a signifcant reduction of BPIs from 7.4% to 1.3% (p < 0.01).After suitable training, they could even reduce permanent BPIs to 0% [5].
Perineal tears III °/IV °have a prevalence rate from 0.6% to 8% [6].Shoulder dystocia and internal manoeuvres were associated with a three-fold increase in the risk of OASIS (obstetric anal sphincter injuries) [7].However, there are no studies investigating if training for managing shoulder dystocia can reduce perineal tears III °/IV °for the mother.
Tis is a prospective and retrospective observational cohort study to test the hypothesis that PROMPT minimizes the mother's permanent brachial plexus injury and birth injuries after 2 and 1/2 years of training at the Hannover Medical School.

Methods
In this prospective observational cohort study, we compared the frequencies of shoulder dystocia, permanent brachial plexus injury, and perineal tears III °/IV °following the introduction of PROMPT at the Hanover Medical School in 2017 with retrospective data from 2004.
Te impact of training following its introduction was assessed by comparing complication rates before and after the implementation.All infants born during 16 years, from January 1 st , 2004, until December 31 st , 2019, were identifed using a computerized fetal database (Viewpoint V.5 and V.6).In addition, all birth books from 2004 until 2019 were examined and checked by hand to identify further cases.All cases of neonates with suspected plexus injury following shoulder dystocia were followed up at the age of one year, and the outcomes were recorded.Te study compared the period "before the training" (group 1) and "after the training" (group 2) regarding the number of shoulder dystocia cases, brachial plexus injuries, asphyxia, and adverse outcomes, as well as the frequency of the manoeuvres performed.In particular, the numbers of perineal tears III °/ IV °, episiotomies, and vaginal operative deliveries were compared.

Statistical Methods.
Te statistical evaluation mainly employed basic descriptive statistics.For qualitative variables, absolute and percent frequencies were given.Te two study groups (before PROMPT and after the initiation of the PROMPT) were contrasted using contingency tables and tested for signifcant diferences using the chi-square test or, if the expected frequencies proved too low, Fisher's exact test was applied.Odds ratios with 95% CI were calculated in case of signifcant diferences.Relative risk reduction was also calculated for all qualitative parameters.Quantitative variables were presented as the mean with standard deviation or the median with range.Tey were tested for normal distribution using the Kolmogorov-Smirnov test.In case of signifcant deviations from the normal distribution, both groups were compared using the Mann-Whitney U test; otherwise, the independent samples t-test was used.
Statistical tests were performed two sided at a signifcance level of 5%.Due to the descriptive nature of the present analysis, no alpha adjustment for multiple testing was applied, and the results were interpreted accordingly.
Statistical analyses were undertaken using IBM SPSS Statistics 26 (SPSS Inc., an IBM Company, Chicago, IL).
Ethical approval was obtained from the Hannover Medical School Ethical Committee (Nr.8268 BO K 2019, 16 th January 2019).

Results
Tere was total of 22.640 vaginal deliveries, 18.031 in group 1 and 4.609 in group 2, respectively.Te main fndings are an increase of cases diagnosed with shoulder dystocia, an increase of release manoeuvres for the anterior shoulder, and in particular a reduction of permanent brachial plexus injuries.Also, episiotomies were performed less frequently but perineal tears III °/IV °increased.
Beside BPI, the second most severe adverse outcome in shoulder dystocia was asphyxia, which had a long-term negative impact on the newborn and the family.Here, the results were unexpected as birth asphyxia increased substantially from 3/48 (6.3%) to 4/23 (17.4%) (p � 0.23); there were, however, no adverse efects of perinatal asphyxia at one year of age in either of the groups.
Te most important fnding for manoeuvres was a statistically signifcant increase in performing McRoberts 1 and 2).Te descriptive analysis showed no signifcant diferences between the groups regarding gestational age, gravida, para, and birthweight, indicating similarity between both populations of infants and mothers.
Te outcome parameters 5′ APGAR score, umbilical artery pH, and base excess were similar in both groups.Te slight increase in maternal blood loss recordings (group 2) may indicate either an increased blood loss or an improved estimation and documentation.However, there were no statistically signifcant diferences between the groups (Table 3).
Te descriptive analysis of both groups showed no demographic diferences between the populations of infants and mothers in the groups.
We applied the national policy and did not apply routine episiotomy in every case of operative vaginal delivery.As a result, while the number of vaginal operative deliveries remained constant, episiotomies decreased substantially and perineal tears III °/IV °increased (Table 5).
PROMPT brakes with the dogma that is rare but severe obstetrics complications cannot be trained.Specifc manoeuvres such as McRoberts, suprapubic pressure, internal rotation, delivery, and the development of the posterior arm are well established to resolve the emergencies, and positive efects have been demonstrated [5,8].Draycott et al. [9] have shown that PROMPT resulted in similar rates of shoulder dystocia before and after the training (2.04% and 2.00%, respectively), but the initiation of release manoeuvres doubled; in particular, McRoberts' manoeuvre (from 29.3% to 87.4%, respectively).Our results are in line with Draycott et al., as McRoberts' manoeuvre increased from 77% to 100%.
Te study of Draycott et al. [9] demonstrated a reduction of brachial plexus injury at birth from 10% to 2.3%.Weiner et al. [10] also showed a similar reduction from 10.7% to 0% in fve years.Again, our study is in line with the results published in the literature following PROMPT, as the total brachial plexus injury at birth went from 14.6% to 4.3% and the permanent BPI from 14.2 to 0%, albeit in small numbers.Tese results show a very promising impact of the training and are the study's most important fndings.Ongoing annual training is, however, mandatory to make these results sustainable [11,12].
Perineal tears III °/IV °can cause serious short-and longterm harm for the mothers, including fecal incontinence [13] and sexual dysfunction [14].Terefore, their prevention is critically important.Te use of episiotomy is a controversial issue.Some observational studies have shown that the use of episiotomy for vaginal births [15] and vaginal operative deliveries (vacuum and forceps) [16] is associated with a risk reduction.However, other evidence has failed to show a protective impact of the episiotomy [6] or an increase of third-and fourth-degree tears associated with episiotomies [17].In particular, the study of Shmueli et al. [18] has shown a 2.26-fold increased incidence of perineal tears III °/IV °following an episiotomy after a spontaneous delivery but no diferences after vaginal operative deliveries.Our analysis showed an increase of perineal tears III °/IV °from 0.51% to 0.85% following the PROMPT with a simultaneous decrease of the use of episiotomy from 29.2% to 18.1%.Tis may indicate a potential protective efect of episiotomies for the risk of perineal tears III °/IV °, particularly in vaginal operative deliveries.As observed, the incidence of vaginal operative deliveries resulting in third-and fourth-degree tears increased from 1.8% to 4% after the training.However, their percentage remained unchanged in both groups at around 7%, while the mean fetal weight increased slightly from 3,517 g to 3,604 g.Tis fnding may be the result of the reduced use of episiotomy.However, other factors, such as Obstetrics and Gynecology International an increase in diabetes [19], maternal weight [20,21], and the improvement in documentation following the PROMPT, may have a role.

Strengths and Limitations.
Te main strength of our research was that it was conducted in a large obstetric centre with around 3000 births annually.A search of the database     Obstetrics and Gynecology International and all birth hard-copy recordings from 2004 provided us with comprehensive data.Also, the training concept included all professional groups involved in labour and childbirth (obstetricians, midwives, neonatologists, paediatric nurses, anaesthetists, anaesthesia nurses, and theatre nurses).Terefore, the whole team worked together using the same management algorithms.Te training was repeated four times annually.
Several limitations have to be mentioned.First, the participation level of staf was low.Over the 2 and 1/2-year period, we observed a total participation rate of only 35.6%.However, among the core staf involved, the participation rates were signifcantly higher, with obstetricians achieving a rate of 50-60% and midwives of 92-100%.
Second, there was a low total number of rare obstetrical complications such as shoulder dystocia cases (71/22,640) and III °/IV °perineal tear cases (131/22,640), limiting the conclusions that can be drawn from this cohort.

Interpretation.
Te authentical use of a scientifcally written and efective training concept, the adaptation of the training materials into the German language taking into account German guidelines and drugs, the use of high fdelity simulators, and the implementation of the PROMPT concept involving teams of midwives, obstetricians, paediatricians, and anaesthesiologists on a labour ward with more than 3,000 deliveries per annum and with a wide variety of high-risk pregnancies have resulted in signifcant improvements after only two and a half years.Tis approach can reduce permanent brachial plexus injury in shoulder dystocia to zero.
Te fndings of the PROMPT introduction at a Germanspeaking university hospital show substantial benefts.Albeit in a relatively small number of cases, the cohort represents the clinical reality in a German setting rather well.

Conclusion
PROMPT signifcantly improves the management of shoulder dystocia and decreases permanent brachial plexus injuries but not perineal tears III °/IV °.Obstetrics and Gynecology International

Table 3 :
Laboratory parameters and demographic characteristics (infants and mothers).

Table 2 :
Brachial plexus injury, asphyxia, and adverse outcomes (infants).: the statistical signifcance calculation is unavailable for these groups (0 cases in group 2).

Table 5 :
Demographic characteristics between group 1 and group 2 (infants and mothers).