Fatal shoulder dystocia: a review of 56 cases reported to the Confidential Enquiry into Stillbirths and Deaths in Infancy

Incidence of shoulder dystocia and risk factors for recurrence in the subsequent pregnancy-A historical register-based cohort study

INTRODUCTION

Shoulder dystocia is a rare obstetric complication, and the risk of recurrence is important for planning future deliveries.

MATERIAL AND METHODS

The objectives of our study were to estimate the incidence and risk factors for recurrence of shoulder dystocia and to identify women at high risk of recurrence in a subsequent vaginal delivery. The study design was a nationwide register-based study including data from the Danish Medical Birth Registry and National Patient Register in the period 2007-2017. Nulliparous women with a singleton fetus in cephalic presentation were included for analysis of risk factors in index and subsequent delivery.

RESULTS

During the study period, 6002 cases of shoulder dystocia were reported with an overall incidence among women with vaginal delivery of 1.2%. Among 222 225 nulliparous women with vaginal births, shoulder dystocia complicated 2209 (1.0%) deliveries. A subsequent birth was registered in 1106 (50.1%) of the women with shoulder dystocia in index delivery of which 837 (77.8%) delivered vaginally. Recurrence of shoulder dystocia was reported in 60 (7.2%) with a six-fold increased risk compared with women without a prior history of shoulder dystocia (risk ratio [RR] 5.70, 95% confidence interval [CI]: 4.41 to 7.38; adjusted RR 3.06, 95% CI: 2.03 to 4.68). Low maternal height was a significant risk factor for recurrence of shoulder dystocia. In the subsequent delivery, significant risk factors for recurrence were birthweight >4000 g, positive fetal weight difference exceeding 250 g from index to subsequent delivery, stimulation with oxytocin and operative vaginal delivery. In the subsequent pregnancy following shoulder dystocia, women who underwent a planned cesarean (n = 176) were characterized by more advanced age and a higher prevalence of diabetes in the subsequent pregnancy. Furthermore, they had more often experienced operative vaginal delivery, severe perineal lacerations, and severe neonatal complications at the index delivery.

CONCLUSIONS

The incidence of shoulder dystocia among nulliparous women with vaginal delivery was 1.0% with a 7.2% risk of recurrence in a population where about 50% had a subsequent birth and of these 78% had subsequent vaginal delivery. Important risk factors for recurrence were low maternal height, increase of birthweight ≥250 g from index to subsequent delivery and operative vaginal delivery.

Obstetric and perinatal outcome in short-stature patients

OBJECTIVE

Scarce data exist regarding obstetric complications of short-stature patients. This study aimed to investigate obstetric and perinatal outcomes in women with short stature; specifically, to investigate whether short-stature patients are at an increased risk for cesarean delivery.

METHODS

A population-based cohort study was conducted, including all singletons born between the years 1991 and 2021 at a tertiary medical center. Obstetric and perinatal outcomes of short-stature patients were compared with those of non-short patients. A generalized estimation equation binary logistic model was constructed to adjust for confounders and maternal recurrence in the cohort.

RESULTS

The study population included 356 356 parturient; among them, 14 035 (3.9%) were short-stature patients. Short-stature patients had significantly higher rates of cesarean delivery (20.7% vs 13.7%, odds ratio = 1.64, 95% confidence interval 1.57-1.71, P < 0.001), induction of labor, pathologic presentations, prolonged second stage of labor, non-reassuring fetal monitoring, and meconium-stained amniotic fluid. Newborns of short-stature patients had a significantly higher risk of being small for gestational age as compared with those of non-short patients. In the generalized estimation equation models, the association between short stature and risk of cesarean delivery remained significant (adjusted odds ratio = 1.32, 95% confidence interval 1.27-1.38, P < 0.001), as well as the risk of small for gestational age newborns (adjusted odds ratio = 1.51, 95% confidence interval 1.40-1.63, P < 0.001), but not for the other adverse outcomes.

CONCLUSIONS

Maternal short stature is an independent risk factor for cesarean delivery and is associated with small for gestational age newborns.

Association between Diabetes in Pregnancy and Shoulder Dystocia by Infant Birth Weight in an Era of Cesarean Delivery for Suspected Macrosomia

OBJECTIVE

 We estimated the association between diabetes and shoulder dystocia by infant birth weight subgroups (<4,000, 4,000-4,500, and >4,500 g) in an era of prophylactic cesarean delivery for suspected macrosomia.

STUDY DESIGN

 A secondary analysis from the National Institute of Child Health and Human Development U.S. Consortium for Safe Labor of deliveries at ≥24 weeks with a nonanomalous, singleton fetus with vertex presentation undergoing a trial of labor. The exposure was either pregestational or gestational diabetes compared with no diabetes. The primary outcome was shoulder dystocia and secondarily, birth trauma with a shoulder dystocia. We calculated adjusted risk ratios (aRRs) with modified Poison's regression between diabetes and shoulder dystocia and the number needed to treat (NNT) to prevent a shoulder dystocia with cesarean delivery.

RESULTS

 Among 167,589 assessed deliveries (6% with diabetes), pregnant individuals with diabetes had a higher risk of shoulder dystocia at birth weight <4,000 g (aRR: 1.95; 95% confidence interval [CI]: 1.66-2.31) and 4,000 to 4,500 g (aRR: 1.57; 95% CI: 1.24-1.99), albeit not significantly at birth weight >4,500 g (aRR: 1.26; 95% CI: 0.87-1.82) versus those without diabetes. The risk of birth trauma with shoulder dystocia was higher with diabetes (aRR: 2.29; 95% CI: 1.54-3.45). The NNT to prevent a shoulder dystocia with diabetes was 11 and 6 at ≥4,000 and >4,500 g, versus without diabetes, 17 and 8 at ≥4,000 and >4,500 g, respectively.

CONCLUSION

 Diabetes increased the risk of shoulder dystocia, even at lower birth weight thresholds than at which cesarean delivery is currently offered. Guidelines providing the option of cesarean delivery for suspected macrosomia may have decreased the risk of shoulder dystocia at higher birth weights.

KEY POINTS

· >Diabetes increased the risk of shoulder dystocia, even at lower birth weight thresholds than at which cesarean delivery is currently offered.. · Cesarean delivery for suspected macrosomia may have decreased the risk of shoulder dystocia at higher birth weights.. · These findings can inform delivery planning for providers and pregnant individuals with diabetes..

Cardiac Asystole at Birth Re-Visited: Effects of Acute Hypovolemic Shock

Births involving shoulder dystocia or tight nuchal cords can deteriorate rapidly. The fetus may have had a reassuring tracing just before birth yet may be born without any heartbeat (asystole). Since the publication of our first article on cardiac asystole with two cases, five similar cases have been published. We suggest that these infants shift blood to the placenta due to the tight squeeze of the birth canal during the second stage which compresses the cord. The squeeze transfers blood to the placenta via the firm-walled arteries but prevents blood returning to the infant via the soft-walled umbilical vein. These infants may then be born severely hypovolemic resulting in asystole secondary to the loss of blood. Immediate cord clamping (ICC) prevents the newborn's access to this blood after birth. Even if the infant is resuscitated, loss of this large amount of blood volume may initiate an inflammatory response that can enhance neuropathologic processes including seizures, hypoxic-ischemic encephalopathy (HIE), and death. We present the role of the autonomic nervous system in the development of asystole and suggest an alternative algorithm to address the need to provide these infants intact cord resuscitation. Leaving the cord intact (allowing for return of the umbilical cord circulation) for several minutes after birth may allow most of the sequestered blood to return to the infant. Umbilical cord milking may return enough of the blood volume to restart the heart but there are likely reparative functions that are carried out by the placenta during the continued neonatal-placental circulation allowed by an intact cord.

Accuracy of Fetal Biacromial Diameter and Derived Ultrasonographic Parameters to Predict Shoulder Dystocia: A Prospective Observational Study

Background and Objectives: Shoulder dystocia (ShD) is one of most dangerous obstetric complication. The objective of this study was to determine if the ultrasonographic fetal biacromial diameter (BA) and derived parameters could predict ShD in uncomplicated term pregnancies. Materials and Methods: We conducted a prospective observational study in a tertiary care university hospital from March 2021 to February 2022. We included all full-term pregnancies accepted for delivery that received an accurate ultrasonography (USG) scan before delivery. USG biometry and estimated fetal weight (EFW) were collected. Therefore, we evaluated the diameter of the mid-arm, the transverse thoracic diameter (TTD) and the biacromial diameter (BA). BA was estimated using Youssef’s formula: TTD + 2 mid-arm diameters. The primary outcome was the evaluation of BA and its related parameters (BA/biparietal diameter (BPD), BA/head circumference (HC) and BA–BPD in fetuses with ShD versus fetuses without ShD. Diagnostic accuracy for ShD of BA, BA/BPD, BA/HC and BA–BPD was evaluated using receiver operator curve (ROC) analysis. Results: 90 women were included in the analysis, four of these had ShD and required extra maneuvers after head delivery. BA was increased in fetuses with ShD (150.4 cm; 95% CI 133.2 cm to 167.6 cm) compared to no-ShD (133.5 cm; 95% CI 130.1 cm to 137.0 cm; p = 0.04). Significant differences were also found between ShD and no-ShD groups for BA/BPD (1.66 (95% CI 1.46 to 1.86) vs. 1.44 (95% CI 1.41 to 1.48); p = 0.04), BA/HC (0.45 (95% CI 0.40 to 0.49) vs. 0.39 (95% CI 0.38 to 0.40); p = 0.01), BA–BPD (60.0 mm (95% CI 42.4 to 77.6 cm) vs. 41.4 (95% CI 38.2 to 44.6); p = 0.03), respectively. ROC analysis showed an overall good accuracy for ShD, with an AUC of 0.821 (p = 0.001) for BA alone and 0.881 (p = 0.001), 0.857 (p = 0.016) and 0.867 (p = 0.013) for BA/BPD, BA–BPD and BA/HC, respectively. Conclusions: BA alone, as well as BA/BPD, BA/HC and BA–BPD might be useful predictors of ShD in uncomplicated term pregnancies. However, such evidence needs extensive confirmation by means of additional studies with large sample sizes, especially in case of pregnancies at high risk for ShD (i.e., gestational diabetes).

Effects of Prestretch on Neonatal Peripheral Nerve: An In Vitro Study

Background  Characterizing the biomechanical failure responses of neonatal peripheral nerves is critical in understanding stretch-related peripheral nerve injury mechanisms in neonates. Objective  This in vitro study investigated the effects of prestretch magnitude and duration on the biomechanical failure behavior of neonatal piglet brachial plexus (BP) and tibial nerves. Methods  BP and tibial nerves from 32 neonatal piglets were harvested and prestretched to 0, 10, or 20% strain for 90 or 300 seconds. These prestretched samples were then subjected to tensile loading until failure. Failure stress and strain were calculated from the obtained load-displacement data. Results  Prestretch magnitude significantly affected failure stress but not the failure strain. BP nerves prestretched to 10 or 20% strain, exhibiting significantly lower failure stress than those prestretched to 0% strain for both prestretch durations (90 and 300 seconds). Likewise, tibial nerves prestretched to 10 or 20% strain for 300 seconds, exhibiting significantly lower failure stress than the 0% prestretch group. An effect of prestretch duration on failure stress was also observed in the BP nerves when subjected to 20% prestretch strain such that the failure stress was significantly lower for 300 seconds group than 90 seconds group. No significant differences in the failure strains were observed. When comparing BP and tibial nerve failure responses, significantly higher failure stress was reported in tibial nerve prestretched to 20% strain for 300 seconds than BP nerve. Conclusion  These data suggest that neonatal peripheral nerves exhibit lower injury thresholds with increasing prestretch magnitude and duration while exhibiting regional differences.

In-vitro stress relaxation response of neonatal peripheral nerves

Characterizing the viscoelastic behavior of neonatal peripheral nerves is critical in understanding stretch-related peripheral nerve injuries (PNIs) in neonates. This study investigated the in-vitro viscoelastic stress relaxation response of neonatal piglet brachial plexus (BP) and tibial nerves at two different strain levels (10% and 20%) and stress relaxation testing durations (90- and 300-seconds). BP and tibial nerves from 20 neonatal piglets were harvested and pre-stretched to either 10% or 20% strain at a dynamic rate of 100 mm/min to simulate conditions, such as shoulder dystocia, that may lead to stretch-related PNIs in neonates. At constant strain, the reduction in stress was recorded for 90- or 300-seconds. The biomechanical data were then fit to a viscoelastic model to acquire the short- and long-term stress relaxation time-constants. Though no significant differences in the degree of stress relaxation were found between the two tested strain levels after 90 seconds in both nerve types, reduction in stress was moderately greater (p = 0.056) at 10% strain than at 20% for BP after 300 seconds. The reduction in stress was significantly higher in nerves subjected to a 300 second testing duration than 90 second for both strain levels and nerve types. When comparing BP and tibial nerve stress relaxation response, BP nerve relaxed significantly more than tibial at both strain levels after 90 seconds, but no significant differences were observed after 300 seconds. Our results confirm that neonatal peripheral nerve tissue is highly viscoelastic. These novel biomechanical data can be incorporated into finite element and computational models studying neonatal PNIs.

Cord Management of the Term Newborn

Keeping the umbilical cord intact after delivery facilitates transition from fetal to neonatal circulation and allows a placental transfusion of a considerable amount of blood. A delay of at least 3 minutes improves neurodevelopmental outcomes in term infants. Although regarded as common sense and practiced by many midwives, implementation of delayed cord clamping into practice has been unduly slow, partly because of beliefs regarding theoretic risks of jaundice and lack of understanding regarding the long-term benefits. This article provides arguments for delaying cord clamping for a minimum of 3 minutes.

Shoulder dystocia, umbilical cord blood gases and neonatal encephalopathy

The interpretation of umbilical cord gases may not be straightforward following shoulder dystocia. We reviewed Perinatal and Maternal Mortality Review Committee data from New Zealand infants with moderate and severe neonatal encephalopathy (NE) for 2010-2017 inclusive. If one or more of: pH of ≤7.1; base excess of ≤-12 mmol/L; or lactate of ≥6 mmol/L were present it was considered an abnormal result. One-third (12/36) of infants born following shoulder dystocia had documented umbilical cord gases within the normal range. It is important for clinicians to be aware of this possibility when assessing newborn infants with NE.

Effect of Implementing a Standardized Shoulder Dystocia Documentation Form on Quality of Delivery Notes

OBJECTIVES

Complete and accurate documentation by the delivering provider in cases of shoulder dystocia is critical for providing clinical information and care to the patient and protecting providers from litigation risks. Standardized forms improve inclusion of certain data elements in the medical record, but the impact on subsequent narrative notes is unknown. We aimed to determine if implementation of a standardized shoulder dystocia documentation form improves obstetric provider written narrative delivery notes.

METHODS

In February 2005, our institution introduced a mandatory, standardized shoulder dystocia form containing 29 discrete data points relevant to shoulder dystocia documentation. We identified all deliveries complicated by shoulder dystocia from 1 year before and 4 years after implementation of this form and analyzed medical records for inclusion of delivery information in both the required form and the narrative delivery notes.

RESULTS

We identified 52 cases before and 100 cases after implementation of the standardized form. Inclusion of elements from the form in narrative delivery notes increased significantly after implementation (P = 0.01). Elements present at higher rates included prepregnancy maternal weight (13% before vs 28% after, P = 0.043), total maternal weight gain (19% vs 36%, P = 0.03), estimated fetal weight (60% vs 77%, P = 0.03), duration of active labor (40% vs 65%, P < 0.01), duration of second stage (27% vs 52%, P < 0.01), and time of delivery from head to body (4% vs 30%, P < 0.01).

CONCLUSIONS

Use of a mandatory shoulder dystocia documentation form is associated with significant improvement in the comprehensiveness of delivering provider narrative notes and may encourage more complete and accurate charting. Such improvements can allow for more complete and accurate explanation of events to patients and better demonstrate adherence to standards of care in the management of shoulder dystocia and may improve litigation defensibility.

Shoulder Dystocia during Delivery and Long-Term Neurological Morbidity of the Offspring

OBJECTIVE

The study aimed to evaluate risk factors and implications of shoulder dystocia (SD) on the neurological outcome of successfully delivered offspring.

STUDY DESIGN

This is a cohort analysis including 207,571 deliveries. Risk factors for SD were evaluated using general estimation equation multivariable analyses. Offspring hospitalization incidence up to age 18 years due to neurological conditions was compared between both groups. Kaplan-Meyer curve was used to assess the cumulative hospitalization incidence. Cox proportional hazards model was used to control for confounders.

RESULTS

SD complicated 0.2% (n = 353) of deliveries included in the study (n = 207,571). Risk factors for SD were fetal macrosomia, maternal diabetes mellitus, male gender, and advanced maternal age (p < 0.05 for all). Higher perinatal mortality was observed among SD cases (2.8 vs. 0.4%, p < 0.001). In most of the investigated neurological conditions no significant differences were found between the groups. Comparable rates of cumulative neurological-related hospitalization were observed (log rank p-value = 0.342) as well as lack of association between SD and neurological hospitalization (adjusted HR = 0.73; 95% CI 0.36-1.47; p = 0.381) when controlled for gestational age.

CONCLUSION

Risk factors for SD are macrosomia, diabetes mellitus, male gender, and advanced maternal age. SD is not associated with long-term neurological morbidity of the offspring.

Favorable outcome after nine minutes of shoulder dystocia preceded by a tight nuchal cord

Objectives

A case report involving a tight nuchal cord and concomitant shoulder dystocia with a review of the literature. We demonstrate that favorable outcomes may result with correct application of maneuvers and adequate management after delivery.

Case presentation

A 41 years old woman was admitted with spontaneous rupture of membranes. The first stage of labor was unremarkable. During the second stage, an intentionally-cut tight nuchal cord was followed by 9 min of shoulder dystocia that was finally relieved by delivery of the anterior shoulder. APGAR scores were 0, 3, 4, 7 at 1, 5, 10 and 20 min respectively. The neonate was placed under therapuetic hypothermia and was discharged after 13 days. At 5 months and 1.5 years of age, the infant met age appropriate developmental milestones with no neurologic sequela.

Conclusions

Shoulder dystocia can result in fatal outcomes for the neonate. Adequate management highlights the need for prompt recognition of this complication and application of appropriate maneuvers. Therapeutic hypothermia decreases mortality and improves neurological development in infants who experience hypoxic ischemic encephalopathy (HIE).

Guideline No. 392-Pregnancy and Maternal Obesity Part 2: Team Planning for Delivery and Postpartum Care

OBJECTIVE

This guideline will review key aspects in the pregnancy care of women with obesity. Part I will focus on Preconception and Pregnancy Care. Part II will focus on Team Planning for Delivery and Postpartum Care.

INTENDED USERS

All health care providers (obstetricians, family doctors, midwives, nurses, anaesthesiologists) who provide pregnancy-related care to women with obesity.

TARGET POPULATION

Women with obesity who are pregnant or planning pregnancies.

EVIDENCE

Literature was retrieved through searches of Statistics Canada, Medline, and The Cochrane Library on the impact of obesity in pregnancy on antepartum and intrapartum care, maternal morbidity and mortality, obstetric anaesthesia, and perinatal morbidity and mortality. Results were restricted to systematic reviews, randomized controlled trials/controlled clinical trials, and observational studies. There were no date or language restrictions. Searches were updated on a regular basis and incorporated in the guideline to September 2018. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology assessment-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies.

VALIDATION METHODS

The content and recommendations were drafted and agreed upon by the authors. Then the Maternal-Fetal Medicine Committees peer reviewed the content and submitted comments for consideration, and the Board of the Society of Obstetricians and Gynaecologists of Canada (SOGC) approved the final draft for publication. Areas of disagreement were discussed during meetings at which time consensus was reached. The level of evidence and quality of the recommendation made were described using the Evaluation of Evidence criteria of the Canadian Task Force on Preventive Health Care.

BENEFITS, HARMS, AND COSTS

Implementation of the recommendations in these guidelines may increase obstetrical provider recognition of the issues affecting pregnant individuals with obesity, including clinical prevention strategies, communication between the health care team, the patient and family as well as equipment and human resource planning. It is hoped that regional, provincial and federal agencies will assist in the education and support of coordinated care for pregnant individuals with obesity.

GUIDELINE UPDATE

SOGC guideline will be automatically reviewed 5 years after publication. However, authors can propose another review date if they feel that 5 years is too short/long based on their expert knowledge of the subject matter.

SPONSORS

This guideline was developed with resources funded by the SOGC.

SUMMARY STATEMENTS

RECOMMENDATIONS.

The Carit Maneuver: A Novel Approach for the Relief of Shoulder Dystocia-A Case Series

Objective  The main purpose of this article is to describe the technique and mechanism of action of a novel intervention for the relief of shoulder dystocia we are labeling Carit maneuver. Methods  We report a cohort study of eight cases of shoulder dystocia not relieved by the combination of McRobert's maneuver and suprapubic pressure treated with the Carit maneuver. This intervention involves the use of the fetal head and neck as the grasping point of the fetus to exert a ventral rotation of the fetal trunk, reduce the bi-acromial diameter, and deliver the posterior shoulder by passive displacement. In all these cases, the direction of the original head restitution, direction of exerted rotation, and side and location of delivery of the first shoulder were recorded. Maternal and neonatal outcomes were reviewed and reported. Results  In all cases, the Carit rotational maneuver resulted in the delivery of the posterior shoulder in the transverse (4), oblique anterior (2), or direct anterior (2) diameters. No instances of neonatal depression or fetal acidemia were noted in this cohort. Conclusion  The Carit maneuver is an original and successful intervention in the management of shoulder dystocia unresponsive to McRobert's maneuver and suprapubic pressure.

Intrapartum Asphyxiated Newborns Without Fetal Heart Rate and Cord Blood Gases Abnormalities: Two Case Reports of Shoulder Dystocia to Reflect Upon

Our report covers two cases of severe hypoxic-ischemic encephalopathy in newborns whose birth was complicated by shoulder dystocia. In both cases, there were inconsistencies observed among cardiotocographic traces, baby's clinical conditions at birth, and umbilical cord blood gases. Namely, normal cardiotocographic monitoring and cord pH > 7, in spite of the fact that the newborns were severely depressed at birth and their blood gases evaluated within 1 h from birth showed a severe metabolic acidosis. Moreover, one of the two newborns displayed moderately low hemoglobin levels. Metabolic and infectious causes were ruled out. Both newborns developed severe hypoxic-ischemic encephalopathy and received therapeutic hypothermia for 72 h. Both survived, one with a severe dystonic cerebral palsy whereas the other developed only a mild developmental delay in language. Cardiac asystole theory could explain these two cases, reinforcing the need for specific resuscitation guidelines for infants experiencing a birth complicated by shoulder dystocia.

Three Principles Informing Simulation-Based Continuing Education to Promote Effective Interprofessional Collaboration: Reorganizing, Reframing, and Recontextualizing

INTRODUCTION

Shoulder dystocia is a complex birth emergency where patient outcomes remain a concern. This article investigates the detailed processes of simulation-based continuing education in a hospital where evidence over 10 years demonstrates improvements in practitioner knowledge, enacted practices, and maternal and child outcomes.

METHODS

Data were collected by video recording teams participating in a shoulder dystocia simulation and debrief. Analysis combined grounded thematic development with purposive coding of enactments of a relevant protocol (the ALSO HELPERR).

RESULTS

Three themes were identified (three Rs) that capture how effective interprofessional collaboration is promoted through collectively oriented reflection: Reorganizing roles and responsibilities between team members; Reframing the problem of shoulder dystocia from individuals correctly following a protocol, to a team of professionals who need to attune to, respond to, and support one another; and Recontextualizing by collectively "commingling" theoretical knowledge with practical experience to reflect on actions and judgements.

DISCUSSION

The three Rs are relevant to diverse clinical settings and address gaps in knowledge relating to the process of interprofessional simulation. Together, they constitute a set of principles to inform the design and conduct of continuing education for interprofessional practice through simulation.

Directive clinique No 392 - Grossesse et obésité maternelle Partie 2 : Planification en équipe de l'accouchement et soins post-partum

OBJECTIF

La présente directive clinique aborde les aspects essentiels des soins prénataux chez les femmes atteintes d'obésité. La partie 1 porte sur la préconception et les soins prénataux. La partie 2 porte sur la planification en équipe de l'accouchement et les soins post-partum. UTILISATEURS CONCERNéS: Tous les fournisseurs de soins de santé (obstétriciens, médecins de famille, sages-femmes, infirmières, anesthésiologistes) qui prodiguent des soins relatifs à la grossesse auprès de femmes atteintes d'obésité.

POPULATION CIBLE

Femmes atteintes d'obésité qui sont enceintes ou prévoient le devenir. DONNéES PROBANTES: Des recherches ont été menées en consultant les ressources de Statistique Canada, de Medline et de Cochrane Library en vue d'en tirer la littérature relativement aux effets de l'obésité durant la grossesse sur les soins prénataux et intrapartum, la morbidité et la mortalité maternelles, l'anesthésie obstétricale ainsi que sur la morbidité et la mortalité périnatales. Seuls les résultats de revues systématiques, d'essais cliniques randomisés ou comparatifs et d'études observationnelles ont été retenus. Aucune restriction de date ou de langue n'a été employée. Les recherches ont été mises à jour régulièrement, et les résultats ont été incorporés à la directive clinique jusqu'en septembre 2018. Nous avons également tenu compte de la littérature grise (non publiée) obtenue sur les sites Web d'organismes d'évaluation des technologies de la santé et d'autres organismes pertinents, dans des collections de directives cliniques et des registres d'essais cliniques, et auprès d'associations nationales et internationales de médecins spécialistes. MéTHODES DE VALIDATION: Le contenu et les recommandations ont été rédigés et acceptés par les auteurs. Les membres du comité de médecine fœto-maternelle ont ensuite passé en revue le contenu et formulé des commentaires aux fins d'examen. Enfin, le conseil d'administration de la Société des obstétriciens et gynécologues du Canada (SOGC) a approuvé la publication de la version définitive de la directive. Les points de désaccord ont été abordés lors de réunions pour enfin arriver à un consensus. La qualité des données et des recommandations a été déterminée à l'aide des critères d'évaluation décrits par le Groupe d'étude canadien sur les soins de santé préventifs. AVANTAGES, PRéJUDICE ET COûTS: La mise en place des recommandations des présentes directives peut améliorer la reconnaissance des fournisseurs de soins obstétricaux relativement aux problèmes qui touchent les personnes enceintes atteintes d'obésité, notamment au moyen de stratégies de prévention clinique; de la communication entre l'équipe de soins de santé, la patiente et la famille; et de la planification de l'équipement et des ressources humaines. Il est à espérer que les organismes régionaux, provinciaux et fédéraux participeront à la formation et au soutien en matière de soins coordonnés pour les personnes enceintes atteintes d'obésité. MISE à JOUR DE LA DIRECTIVE CLINIQUE: Les directives de la SOGC sont automatiquement passées en revue 5 ans après leur publication. Les auteurs peuvent toutefois proposer une autre date de réévaluation s'ils croient qu'une période de 5 ans est trop courte ou trop longue en fonction de leurs connaissances du sujet à titre d'experts en la matière.

PROMOTEURS

La présente directive a été élaborée à l'aide de ressources financées par la SOGC. DéCLARATIONS SOMMAIRES: RECOMMANDATIONS.

Shoulder dystocia: incidence, mechanisms, and management strategies

Shoulder dystocia can lead to death or brain damage for the baby. Traction on the head can damage the brachial plexus. The diagnosis should be made when the mother cannot push the shoulders out with her own efforts with the next contraction after delivery of the head. There should be no traction on the head to diagnose shoulder dystocia. McRoberts’ position is acceptable but it should not be accompanied by any traction on the head. If the posterior shoulder is in the sacral hollow then the best approach is to use posterior axillary traction to deliver the posterior shoulder and arm. If both shoulders are above the pelvic brim, the posterior arm should be brought down with Jacquemier’s maneuver. If that fails, cephalic replacement or symphysiotomy is the next step. After shoulder dystocia is resolved, one should wait 1 minute or so to allow placental blood to return to the baby before cutting the umbilical cord.

Clinical features of a fatal shoulder dystocia: The hypovolemic shock hypothesis

Shoulder dystocia is a rare but severe obstetric complication associated with an increased risk of brachial plexus palsies, fractures of the clavicle and humerus, hypoxic-ischemic encephalopathy and, rarely, neonatal death. Here we describe a fatal case of shoulder dystocia in a term newborn, although labor was uneventful, fetal heart rate tracing was normal until the delivery of the head and the head-to-body delivery interval (HBDI) occurred within 5 min. Full resuscitation was performed for 35 min without success. Hemoglobin concentration evaluated on the umbilical cord still attached to the placenta was within normal range, while neonatal venous hemoglobin concentration blood gases at 9 min of life showed severe metabolic acidosis and anemia. As previously described by others, our case supports the hypothesis of a hypovolemic shock as the cause of neonatal death, probably due to acute placental retention of fetal blood. The death of the newborn following shoulder dystocia is an event that still presents numerous gaps in knowledge. Further research should focus on.

Shoulder Dystocia Delivery by Emergency Medicine Residents: A High-fidelity versus a Novel Low-fidelity Simulation Model-A Pilot Study

BACKGROUND

Shoulder dystocia (SD) requires emergent intervention to prevent maternal and fetal harm, and simulation models for training can be expensive. We developed a novel, cheap and easily transportable low-fidelity simulation (LFS) model to compare to a commercially available high-fidelity simulation (HFS) model.

METHODS

Emergency medicine residents were randomized to training on the HFS or novel LFS model. Subjects completed a pretest and a 1-week and 6-month posttest including a self-assessment and a simulated SD delivery.

RESULTS

Twenty-seven of the 43 residents completed the study (63%). The number of individuals performing dangerous maneuvers at baseline was similar, 1 week after training was five in HFS and 11 in LFS (p = 0.08) groups and at 6 months was again similar between groups. Mean checklist scores for appropriate actions increased 1 week after training but returned to baseline by 6 months and were similar between groups. The rate of successful delivery, median time to successful delivery, and maximum force applied improved at 1 week and was sustained at 6 months in both groups.

CONCLUSION

Within our limited study population, we did not find a large difference in the occurrence of dangerous actions during simulated SD delivery following HFS and LFS training. Our novel and easily transportable LFS trainer, assembled for less than US$10 each, may be a useful tool to train inexperienced providers on the steps of this procedure. However, this requires further study, as does whether HFS models with force monitoring capabilities may be helpful to train providers to minimize dangerous maneuvers such as the application of excessive force.

[Simulation' benefits in obstetrical emergency: Which proof level?]

Simulation in obstetrical emergency is in expansion. The important economic and human cost in simulation needs a real evaluation about enhancement in technical and non-technical skills, maternal and neonatal morbidity and mortality. We present a literature review of the results published on the subject in shoulder dystocia, post-partum haemorrhage, eclampsia and cord prolaps with a selection of publications with high evidence level or positive impact of training on obstetrical emergencies. There are few publications with a positive impact of training on obstetrical emergencies. Some publications from 10years by the same obstetrical team for training and shoulder dystocia reveal a 75% reduction in brachial plexus injury after 4years of training, and 100% reduction in permanent injury after a decade of training. Only one publication is in accordance with a reduction of severe post-partum haemorrhage with training. For all obstetrical emergencies, crew resource management (communication, self-confidence…) and team training are improved.

Resuscitating the Baby after Shoulder Dystocia

Background. To propose hypovolemic shock as a possible explanation for the failure to resuscitate some babies after shoulder dystocia and to suggest a change in clinical practice. Case Presentation. Two cases are presented in which severe shoulder dystocia was resolved within five minutes. Both babies were born without a heartbeat. Despite standard resuscitation by expert neonatologists, no heartbeat was obtained until volume resuscitation was started, at 25 minutes in the first case and 11 minutes in the second. After volume resuscitation circulation was restored, there was profound brain damage and the babies died. Conclusion. Unsuspected hypovolemic shock may explain some cases of failed resuscitation after shoulder dystocia. This may require a change in clinical practice. Rather than immediately clamping the cord after the baby is delivered, it is proposed that (1) the obstetrician delay cord clamping to allow autotransfusion of the baby from the placenta and (2) the neonatal resuscitators give volume much sooner.

Shoulder dystocia: prediction and management

Shoulder dystocia is a complication of vaginal delivery and the primary factor associated with brachial plexus injury. In this review, we discuss the risk factors for shoulder dystocia and propose a framework for the prediction and prevention of the complication. A recommended approach to management when shoulder dystocia occurs is outlined, with review of the maneuvers used to relieve the obstruction with minimal risk of fetal and maternal injury.

Effectiveness of team training in managing shoulder dystocia: a retrospective study

OBJECTIVES

To evaluate the effectiveness of simulation team training for the management of shoulder dystocia. Primary outcome measures were the number of reported cases of shoulder dystocia, as well as fetal injury that occurred from it. Secondary outcome is documentation of manoeuvres used to alleviate shoulder dystocia.

METHODS

Retrospective cohort study in a teaching hospital in the Netherlands, in a 38 month period before and after implementation of team training.

RESULTS

We compared 3492 term vaginal cephalic deliveries with 3496 deliveries before and after team training. Incidence of shoulder dystocia increased from 51 to 90 cases (RR 1.8 (95% CI: 1.3-2.5)). Fetal injury occurred in 16 and eight cases, respectively (RR 0.50 (95% CI: 0.21-1.2)). Before team training started, the all-fours manoeuvre was never used, while after team training it was used in 41 of 90 cases (45%). Proper documentation of all manoeuvres used to alleviate shoulder dystocia significantly increased after team training (RR 1.6 (95% CI: 1.05-2.5)).

CONCLUSIONS

Simulation team training increased the frequency of shoulder dystocia, facilitated implementation of the all-fours technique, improved documentation of delivery notes and may have a beneficial effect on the number of children injured due to shoulder dystocia.

[Management of shoulder dystocia]

OBJECTIVE

The objective of this review is to propose recommendations on the management of shoulder dystocia.

MATERIALS AND METHODS

The PubMed database, the Cochrane Library and the recommendations from the foreign obstetrical societies or colleges have been consulted.

RESULTS

In case of shoulder dystocia, if the obstetrician is not present at delivery, he should be systematically informed as quickly as possible (professional consensus). A third person should also be called for help in order to realize McRoberts maneuver (professional consensus). The patient has to be properly installed in gynecological position (professional consensus). It is recommended not to pull excessively on the fetal head (grade C), do not perform uterine expression (grade C) and do not realize inverse rotation of the fetal head (professional consensus). McRoberts maneuver, with or without a suprapubic pressure, is simple to perform, effective and associated with low morbidity, thus, it is recommended in the first line (grade C). Regarding the maneuvers of the second line, the available data do not suggest the superiority of one maneuver in relation to another (grade C). We proposed an algorithm; however, management should be adapted to the experience of the operator. If the posterior shoulder is engaged, Wood's maneuver should be performed preferentially; if the posterior shoulder is not engaged, delivery of the posterior arm should be performed preferentially (professional consensus). Routine episiotomy is not recommended in shoulder dystocia (professional consensus). Other second intention maneuvers are described. It seems necessary to know at least two maneuvers to perform in case of shoulder dystocia unresolved by the maneuver McRoberts (professional consensus).

CONCLUSION

All physicians and midwives should know and perform obstetric maneuvers if needed quickly but without precipitation.

Risk factors profile of shoulder dystocia in oman: a case control study

OBJECTIVE

This study aimed to assess the risk factor profile of shoulder dystocia and associated neonatal complications in Oman, a developing Arab country.

METHODS

A retrospective case-control study was conducted among 111 cases with dystocia and 111 controls, identified during 1994-2006 period in a tertiary care hospital in Oman. Controls were randomly selected among women who did not have dystocia, and were matched to cases on the day of delivery. Data related to potential risk factors, delivery, and obstetric complications were collected.

RESULTS

Dystocia was significantly associated with older maternal age, higher parity, larger BMI, diabetes, and previous record of dystocia. In addition, dystocia was associated more with vacuum and forceps deliveries. Routine traction (51%) was the most used manoeuvre. Among dystocia cases, 13% were associated with fetal complications of which Erb's Palsy was the most prevalent (79%).

CONCLUSION

Our finding of significant associations with risk factors lays out the ground to develop a predictability index for shoulder dystocia, which would help in making it preventable. Further p rospective studies are required to confirm the obtained results.

Complications of shoulder dystocia

Complications of shoulder dystocia are divided into fetal and maternal. Fetal brachial plexus injury (BPI) is the most common fetal complication occurring in 4-40% of cases. BPI has also been reported in abdominal deliveries and in deliveries not complicated by shoulder dystocia. Fractures of the fetal humerus and clavicle occur in about 10.6% of cases of shoulder dystocia and usually heal with no sequel. Hypoxic ischemic brain injury is reported in 0.5-23% of cases of shoulder dystocia. The risk correlates with the duration of head-to-body delivery and is especially increased when the duration is >5 min. Fetal death is rare and is reported in 0.4% of cases. Maternal complications of shoulder dystocia include post-partum hemorrhage, vaginal lacerations, anal tears, and uterine rupture. The psychological stress impact of shoulder dystocia is under-recognized and deserves counseling prior to home discharge.

Shoulder dystocia: management and documentation

Shoulder dystocia is an obstetric emergency that occurs when the fetal shoulders become impacted at the pelvic inlet. Management is based on performing maneuvers to alleviate this impaction. A number of protocols and training mnemonics have been developed to assist in managing shoulder dystocia when it occurs. This article reviews the evidence regarding the performance, timing, and sequence of these maneuvers; reviews the mechanism of fetal injury in relation to shoulder dystocia; and discusses issues concerning documentation of the care provided during this obstetric emergency.

Fetal macrosomia and shoulder dystocia in women with gestational diabetes: risks amenable to treatment?

Fetal macrosomia and maternal diabetes are independent risk factors for shoulder dystocia, an obstetrical emergency that may cause permanent neonatal injury. Randomized trials of glycemic control in pregnancies complicated by gestational diabetes reveal decreased rates of macrosomia and shoulder dystocia among those treated. However, definitions of gestational diabetes vary and a specific glycemic threshold for clinically significant risk reduction remains to be delineated. This review discusses risks associated with gestational diabetes including macrosomia (birth weight above 4000-4500 g) and delivery-related morbidity, specifically, shoulder dystocia. Subsequently, we will review recent randomized trials assessing the impact of glycemic control on these delivery-related morbidities. Finally, we will examine a large observational study that found associations with delivery-related morbidity and hyperglycemia below current diabetic thresholds, observations which may suggest reexamination of current diagnosis guidelines for gestational diabetes.

Rethinking placental transfusion and cord clamping issues

A brief delay in clamping the umbilical cord results in a placental transfusion that supplies the infant with a major source of iron during the first few months of life. Cord circulation continues for several minutes after birth and placental transfusion results in approximately 30% more blood volume. Gravity influences the amount of placental transfusion that an infant receives. Placing the infant skin-to-skin requires a longer delay of cord clamping (DCC) than current recommendations. Uterotonics are not contraindicated with DCC. Cord milking is a safe alternative to DCC when one must cut the cord prematurely. Recent randomized controlled trials demonstrate benefits for term and preterm infants from DCC. The belief that DCC causes hyperbilirubinemia or symptomatic polycythemia is unsupported by the available research. Delay of cord clamping substantively increases iron stores in early infancy. Inadequate iron stores in infancy may have an irreversible impact on the developing brain despite oral iron supplementation. Iron deficiency in infancy can lead to neurologic issues in older children including poor school performance, decreased cognitive abilities, and behavioral problems. The management of the umbilical cord in complex situations is inconsistent between birth settings. A change in practice requires collaboration between all types of providers who attend births.

[Prediction, prevention and management of shoulder dystocia]

Shoulder dystocia is one of the most tragic, fatal and unexpected obstetrical events, which is mostly unpredictable and unpreventable. This clinical picture is defined as a delivery that requires additional obstetric maneuvers to release the shoulders after gentle downward traction has failed. Shoulder dystocia occurs when the fetal shoulder impacts on the maternal symphysis or sacral promontory. The incidence of shoulder dystocia is 0.2-0.6%. High perinatal mortality and morbidity is associated with the condition, even when it is managed appropriately. Obstetricians should be aware of the existing risk factors, but should always be alert to the possibility of shoulder dystocia in all labors. Maternal morbidity is also increased, particularly postpartum hemorrhage, rupture of the uterus, injury of the bladder, urethra and the bowels and fourth-degree perineal tears. Complications of the newborn include asphyxia, perinatal mortality, fracture of the clavicula and the humerus. Brachial plexus injuries are one of the most important fetal complications of shoulder dystocia, complicating 4-16% of such deliveries. The purpose of this article is to review the current evidence regarding the possible prediction, prevention and management of shoulder dystocia.

Risk of shoulder dystocia: associations with parity and offspring birthweight. A population study of 1 914 544 deliveries

OBJECTIVES

We estimated the associations of parity and offspring birthweight with the risk of shoulder dystocia, and studied whether the association of offspring birthweight differed by parity.

DESIGN

Population-based register study.

SETTING

The Medical Birth Registry of Norway was used to identify all deliveries between 1967 and 2006.

POPULATION

All vaginal deliveries of a singleton offspring in cephalic presentation during the period 1967-2006 (n=1,914,544).

MAIN OUTCOME MEASURE

Shoulder dystocia at delivery.

RESULTS

Shoulder dystocia occurred in 0.68% (13,109/1,914,544) of all deliveries. There was a strong positive association of birthweight with risk of shoulder dystocia, and 75% (9765/13,109) of all cases occurred in deliveries of offspring weighing 4000g or more. The association of birthweight displayed similar patterns across parities, but the association was slightly stronger in parous than in primiparous women. Among first-time mothers, 0.12% (320/276,614) with offspring weighing 3000-3499g (reference) experienced shoulder dystocia, compared with 13.30% (169/1244) with offspring birthweight higher than 5000g [odds ratio (OR) 135.7, 95%CI 111.6-165.1]. The corresponding results for women with one previous delivery were 0.08% (161/201,572) and 16.45% (501/3054) (OR 246.4, 95%CI 205.4-295.5).

CONCLUSIONS

High offspring birthweight is the major risk factor for shoulder dystocia, constituting most cases. The positive association of birthweight with shoulder dystocia showed similar patterns across parities, but high birthweight parous women were at greater risk of shoulder dystocia compared with primiparous women.

Relationship between head-to-body delivery interval in shoulder dystocia and neonatal depression

OBJECTIVE

To evaluate the relationship between the head-to-body delivery interval in shoulder dystocia, persistent brachial plexus injury, and neonatal depression.

METHODS

We compared the head-to-body delivery intervals in 127 cases of uncomplicated shoulder dystocia-identified using medical record coding and verified by chart review in a university--affiliated community hospital--with a series of 55 medical-legal cases of shoulder dystocia with persistent brachial plexus injury, 14 of which included neonatal depression. Neonatal depression was defined as the presence of any of the following: fetal demise, cardiopulmonary resuscitation, intubation, umbilical artery pH lower than 7.00, or 5-minute Apgar score of 5 or lower.

RESULTS

In the uncomplicated shoulder dystocia group, the median head-to-body delivery interval was 1.0 minute (interquartile range 0.5-1.0). The median for neonates with persistent brachial plexus injury and no depression was 2.0 minutes (interquartile range 1.0-4.0). For those with both persistent brachial plexus injury and neonatal depression, the median was significantly longer at 5.3 minutes (interquartile range 3.9-13.3), P<.001.

CONCLUSION

Neonates born with persistent brachial plexus injury and neonatal depression after shoulder dystocia had longer head-to-body delivery intervals than those with uncomplicated shoulder dystocia or shoulder dystocia with persistent brachial plexus injury without depression. By 4 minutes, all of the neonates with uncomplicated shoulder dystocia were born. Conversely, the majority of neonates with depression-57%-had head-to-body delivery intervals greater than 4 minutes. Such information offers guidance to clinicians caught between the admonition to apply only gentle force when utilizing maneuvers to accomplish a shoulder dystocia delivery and the countervailing need to achieve delivery within a critical time frame to prevent hypoxic injury.

LEVEL OF EVIDENCE

III.

Reducing the risk of shoulder dystocia and associated brachial plexus injury

Despite persisting controversy over shoulder dystocia prediction, prevention, and injury causation, the authors find considerable evidence in recent research in the field to recommend additional guidelines beyond the current American College of Obstetricians and Gynecologists and Royal College of Obstetricians and Gynecologists guidelines to improve clinical practice in managing patients at risk for experiencing shoulder dystocia. In this article, the authors offer health care providers information, practical direction, and advice on how to limit shoulder dystocia risk and, more importantly, to reduce adverse outcome risk.

The “All-Fours” Maneuver for the Management of Shoulder Dystocia

The “all fours” maneuver for managing shoulder dystocia appears to be a rapid, safe and effective technique in women in labor with this problem. We report a case of shoulder dystocia managed successfully with complete vaginal delivery and no injury to mother and newborn after using the “all fours” maneuver. A brief literature review includes descriptions of other maneuvers for the problem of shoulder dystocia.

Head-to-body delivery interval and risk of fetal acidosis and hypoxic ischaemic encephalopathy in shoulder dystocia: a retrospective review

OBJECTIVE

To examine the association between head-to-body delivery interval (HBDI) and cord arterial pH and base excess (BE), and the risk of development of hypoxic ischaemic encephalopathy (HIE).

DESIGN

Retrospective review.

SETTING

A university hospital.

POPULATION

Pregnancies complicated with shoulder dystocia during the period 1995-2009.

METHODS

Cases were identified from a search of the hospital electronic delivery records. Cord arterial pH and BE, and the incidence of HIE and perinatal death, were retrieved from medical records and correlated with HBDI, birth weight, mode of delivery and presence of nonreassuring fetal heart rate pattern and maternal diabetes using univariate analysis, followed by multivariate analysis.

MAIN OUTCOME MEASURES

Any association between cord pH and HBDI.

RESULTS

Of the 200 cases identified, the mean (standard deviation) HBDI was 2.5 minutes (1.5 minutes). Both HBDI and the presence of nonreassuring fetal heart rate pattern were independent factors for pH, and HBDI was the only significant factor for BE. Arterial pH dropped at a rate of 0.011 per minute [95% confidence interval (95% CI), 0.017-0.004; P = 0.002] with HBDI. The mode of delivery, birth weight and maternal diabetes did not affect blood gas levels. The respective risks of severe acidosis (pH < 7) and HIE with HBDI of <5 minutes were 0.5% and 0.5% versus 5.9% and 23.5% with HBDI ≥ 5 minutes.

CONCLUSIONS

Cord arterial pH drops with HBDI during shoulder dystocia, but the risk of acidosis or HIE is very low with HBDI < 5 minutes.

SIMULATION TRAINING FOR OBSTETRIC PROCEDURES AND EMERGENCIES

The World Health Organisation (WHO) has estimated that 1500 women die every day from preventable complications of pregnancy and childbirth. While barriers to accessing healthcare are undoubtedly multi-factorial, studies have repeatedly shown that providing skilled healthcare workers can result in untold benefits for women and babies in developing countries. The phenomenon of preventable maternal and fetal morbidity and mortality is not limited to the developing world. The Confidential Enquiries into Maternal Deaths (CEMD) and Stillbirths and Infant Deaths (CESDI) in the UK have repeatedly identified substandard care as a major contributor to maternal and neonatal mortality. In 2008 The King's Fund publishedSafe Births: Everybody's business,an independent enquiry into the safety of maternity services in England. This recommended that simulation-based training to assess clinical, communication and team skills should be available to all maternity staff, and that training should form a core activity. Many hospitals in the UK have been running in-house courses for staff for over a decade with measurable improvements in neonatal outcomes. The value of these training schemes is recognised and rewarded through reduced insurance premiums for participating hospital trusts as part of clinical negligence schemes. Gaining competence in managing obstetric emergencies presents particular challenges for trainees. Most emergencies are, thankfully, uncommon but some constitute life-threatening events where management naturally falls to the most experienced available clinician. The skills required are often particular to emergencies and therefore novel to trainees. Utilising emergencies as training opportunities is further complicated by the presence of a conscious patient.

Contemporary Management of Shoulder Dystocia

Shoulder dystocia is an uncommon but potentially catastrophic intrapartum event. Although risk factors such as maternal diabetes, obesity and macrosomia can be identified, shoulder dystocia most frequently occurs in patients who lack risk factors. Many maneuvers have been described to assist the operator in the safe release of the shoulder and subsequent delivery; however, no prospective trials have compared these maneuvers in such a way to suggest that one maneuver is superior to another. This article describes the identification of patients at risk for shoulder dystocia, clinical management of the shoulder dystocia, event documentation and the contemporary use of drills and simulation training to improve team preparedness for this unpredictable and usually unavoidable event.