Shoulder dystocia and the next delivery: Outcomes and management

Objective. To evaluate delivery mode management decisions and the rate of shoulder dystocia recurrence for women with a prior delivery complicated by shoulder dystocia.

Study design. We used a computerized perinatal database and ICD-9 codes to identify all vaginal deliveries complicated by shoulder dystocia from 1996 to 2001. Subsequent deliveries over the next three years were identified and reviewed for relevant clinical, obstetric, and delivery outcomes. Management including use of labor induction, labor augmentation, operative vaginal delivery, and delivery mode (elective cesarean section (CS) vs. trial of labor (TOL)) were reviewed. The recurrence rate of shoulder dystocia was calculated and the characteristics of these cases further described.

Results. Over the initial 5-year study, there were 25 995 vaginal deliveries, 205 shoulder dystocia cases (0.8%), 36 (17.5%) with neonatal injury. Of the 205 initial shoulder dystocia cases, 39 patients had 48 subsequent deliveries at our institution (a subsequent delivery rate of 23% at our institution, significantly less than the overall population (42%, p < 0.001)). Complete data were available for 47 deliveries. Four women had elective CS without labor (one due to prior shoulder dystocia), 43 (91.5%) had a TOL, and 42 (88%) achieved vaginal delivery. Recurrent shoulder dystocia complicated 9.5% (4/42) of deliveries; one case included neonatal brachial plexus injury that resolved prior to hospital discharge. Of the four recurrent shoulder dystocia cases, none were complicated by maternal diabetes, macrosomia, prolonged second stage of labor, or underwent an operative vaginal delivery. No statistically significant univariate differences were seen between the recurrence group and the no-shoulder dystocia vaginal delivery group; however birth weight and nulliparity at initial shoulder dystocia pregnancy jointly demonstrated a relationship of recurrence (p = 0.048).

Conclusion. In TOL cases that result in a vaginal delivery, the rate of recurrence of shoulder dystocia is high—approximately 10 times higher than the rate for the general population. Often the only identifiable risk factor is the prior history itself, which may influence delivery management in subsequent pregnancies. Birth weight and nulliparity at initial shoulder dystocia pregnancy may influence clinical decision-making in cases of prior shoulder dystocia.     

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.     

Shoulder dystocia in a Jamaican cohort

Objective

To assess the risk factors for shoulder dystocia in Jamaica.

Methods

A retrospective cohort analysis of all cases of shoulder dystocia, and birth weight-matched controls identified from January 1, 2000 to December 31, 2004. Multiple factors were analyzed individually and in combination to identify risk factors.

Results

The incidence of shoulder dystocia was 0.83%. Nulliparity, a first stage of labor greater than 7 hours, a second stage lasting more than 1 hour, and use of oxytocin augmentation were found to be statistically significant factors with unadjusted odds ratios (95% confidence interval) of 1.78 (0.86-3.34), 1.89 (0.91-3.94), 2.78 (0.24-31.47), and 1.56 (0.77-3.15), respectively. The incidence of shoulder dystocia decreased as parity increased when adjusted for age.

Conclusion

Individual risk factors for shoulder dystocia remain obscure. The nulliparous pelvis, when controlled for neonatal weight, was associated with a statistically increased risk of shoulder dystocia; this risk decreased with increasing parity.     

肩难产15例回顾性分析

目的:分析肩难产的危险因素,探讨早期预测、识别和处理方法。方法:回顾性分析2000年01月至2010年01月10年间的肩难产病例,并随机抽取同期阴道分娩病例作为对照,比较两组孕妇的产前、产时指标,分娩并发症及新生儿径线、新生儿并发症的区别。结论:巨大儿发生肩难产的比例最高,但根据高危因素仍很难预测肩难产。正确处理肩难产是降低围生儿并发症的重要措施。     

肩难产21例回顾性分析

目的　了解肩难产的发生率 ,并发症及处理方法 ,分析肩难产的高危因素 ,探讨其临床价值。方法　回顾性分析 1997年 1月至 2 0 0 1年 12月 5年间的肩难产病例 ,并随机抽取同期阴道分娩病例作为对照 ,比较两组间孕妇在产前、产时指标和胎儿径线等方面有无差别。分析巨大儿、糖尿病、阴道助产、产程异常等高危因素在肩难产中的比率。评价松解胎肩的方法。结果　 5年间分娩总数为 6 4 0 0例 ,肩难产 2 4例 ,其中巨大儿 12例 ,占5 7 10 %。有 6例并发新生儿损伤 ,占 30 0 0 %。肩难产组和对照组在新生儿体重、身长、头围、胸围有显著差异 ,两组孕妇的宫高和腹围有显著差异。结论　肩难产是产科少见的并发症 ,巨大儿发生肩难产的比例最高 ,但根据高危因素仍很难预测肩难产。正确处理肩难产是降低围生儿并发症的重要措施。     

Shoulder dystocia: Risk factors,predictability, and preventability

Shoulder dystocia remains an unpredictable obstetric emergency, striking fear in the hearts of obstetricians both novice and experienced. While outcomes that lead to permanent injury are rare, almost all obstetricians with enough years of practice have participated in a birth with a severe shoulder dystocia and are at least aware of cases that have resulted in significant neurologic injury or even neonatal death. This is despite many years of research trying to understand the risk factors associated with it, all in an attempt primarily to characterize when the risk is high enough to avoid vaginal delivery altogether and prevent a shoulder dystocia, whose attendant morbidities are estimated to be at a rate as high as 16–48%. The study of shoulder dystocia remains challenging due to its generally retrospective nature, as well as dependence on proper identification and documentation. As a result, the prediction of shoulder dystocia remains elusive, and the cost of trying to prevent one by performing a cesarean delivery remains high. While ultimately it is the injury that is the key concern, rather than the shoulder dystocia itself, it is in the presence of an identified shoulder dystocia that occurrence of injury is most common.     

Shoulder dystocia: a comparison of patients with and without diabetes mellitus

Background: The study was aimed to compare pregnancies complicated with shoulder dystocia, of patients with and without diabetes mellitus. Methods: A comparison of all singleton, vertex, term deliveries between the years 1988–1999, complicated with shoulder dystocia with and without diabetes mellitus was performed. Statistical analysis was done using receiver operating characteristic curve analysis. Results: Using a receiver operating characteristic curve analysis, the area under the curve for birth weight was 0.92 (95% CI 0.90–0.93). However, for birth weight of 4,000 g the sensitivity was only 56% with specificity of 95%. While comparing shoulder dystocia between patients with (n=38) and without diabetes mellitus (n=207), neonates of the diabetic patients were significantly heavier (mean birth weight 4,244.2±515.1 vs. 4,051.6±389.5; P=0.008) and had higher rate of Apgar scores lower than 7 at 1 min (50.0% vs. 25.9%; P=0.030), but not at 5 min (2.6% vs. 2.0%; P=0.083) when compared to the non-diabetic group. No significant differences were noted regarding perinatal mortality between the groups (0% vs. 4.3%; P=0.362). Conclusions: The newborn of the diabetic mother complicated with shoulder dystocia does not appear to be at an increased risk for perinatal morbidity compared with the newborn of the non-diabetic mother. Presented in part at the Society for Gynecologic Investigation 50th Annual Scientific Meeting, Washington, DC, 27–30 March 2003.     

Implementation of a multicenter shoulder dystocia injury prevention program

Although the evidence for supporting the effectiveness of many patient safety practices has increased in recent years, the ability to implement programs to positively impact clinical outcomes across multiple institutions is lagging. Shoulder dystocia simulation has been shown to reduce avoidable patient harm. Neonatal injury from shoulder dystocia contributes to a significant percentage of liability claims. We describe the development and the process of implementation of a shoulder dystocia simulation program across five academic medical centers and their affiliated hospitals united by a common insurance carrier. Key factors in successful roll out of this program included the following: involvement of physician and nursing leadership from each academic medical center; administrative and logistic support from the insurer; development of consensus on curriculum components of the program; conduct of gap and barrier analysis; financial support from insurer to close necessary gaps and mitigate barriers; and creation of dashboards and tracking performance of the program.     

Shoulder dystocia related fetal neurological injuries: the predisposing roles of forceps and ventouse extractions

On the basis of 333 documented cases of permanent perinatal neurological damage, associated with arrest of the shoulders at birth, the authors conducted a retrospective study in order to evaluate the predisposing role, if any, of the utilization of extraction instruments. The investigation revealed that 35% of all injuries occurred in neonates delivered by forceps, ventouse or sequential ventouse–forceps procedures. This frequency was several-fold higher than the prevailing instrument use in the practices of American obstetricians during the same years. A high rate of forceps and ventouse extractions was demonstrable in all birth weight categories. Average weight and moderately large for gestational age fetuses underwent instrumental extractions more often than grossly macrosomic ones. This circumstance indicates that forceps and ventouse are independent risk factors, unrelated to fetal size. Their use entailed central nervous system injuries significantly more often than did spontaneous deliveries. The findings suggest that extraction procedures may be as important as macrosomia among the factors that lead to neurological damage in the child in connection with shoulder dystocia. Because they augment the intrinsic dangers of excessive fetal size exponentially, the authors consider their use in case of ≥4,000 g estimated fetal weight inadvisable. Sequential forceps–ventouse utilization further doubles the risks and is, therefore, to be avoided in all circumstances.     

How to predict recurrent shoulder dystocia

OBJECTIVE: Our aim was to determine the rate and risk factors for recurrent shoulder dystocia. STUDY DESIGN: A retrospective analysis of patients diagnosed with shoulder dystocia was performed by searching a computerized database from January 1, 1993, to June 30, 1999 for the following information: (1) vaginal deliveries, either spontaneous or operative, (2) shoulder dystocia, (3) birth weight, (4) duration of second stage of labor, (5) parity, and (6) gestational diabetes. Statistical analyses included chi(2) and t test. RESULTS: There were 39,681 vaginal deliveries with 602 (1.5%) complicated by shoulder dystocia. Sixty-six patients underwent a subsequent vaginal delivery, and 11 (16.7%) experienced another shoulder dystocia. The odds ratio for a recurrent shoulder dystocia was 10.98 (P <.000001). Nine of the 11 patients with recurrent shoulder dystocia compared with 28 of 55 without a recurrence were nulliparous women in their index pregnancy (P <.001). The mean fetal weights were 3885 g in the recurrent dystocia group and 3702 g in the group without recurrence (P <.03). Gestational age, operative delivery, and gestational diabetes were similar in the two groups. CONCLUSION: Factors that appear to increase the recurrence risk of shoulder dystocia include fetal weight and maternal parity. Prior shoulder dystocia is the single greatest predictive factor.     

Erb's palsy without shoulder dystocia.

OBJECTIVES: The purpose of this commentary is to review certain articles which have provided evidence that Erb's palsy can occur without associated shoulder dystocia. The mechanism of the specific cause of the injury will be described. METHODS: Prior to the last 10-12 years it was assumed that Erb's palsy occurred exclusively with and was the result of shoulder dystocia. Gonik et al. [Am J Perinat 1991;8:31-34], reported on a research study based on the premise that when Erb's palsies occurred there must have been shoulder dystocia present but it went undetected by the delivering physician. Subsequently Gherman [Am J Obstet Gynecol 1998;178:423-427], published a detailed study which carefully looked at multiple aspects of shoulder dystocia including those similar injuries occurring with and without associated shoulder dystocia. RESULTS: Both Gonik's and Gherman's research revealed distinct maternal and newborn differences when comparing Erb's palsy occurring with and without associated shoulder dystocia. These differences, which have nothing to do with the ability to recognize shoulder dystocia, provide conclusive evidence that Erb's palsy does occur without associated shoulder dystocia. CONCLUSIONS: Therefore, Gonik's original premise, that shoulder dystocia must have been present if Erb's palsy occurred, is not supported. This brings into question the cause of Erb's palsy in those cases without shoulder dystocia. The maternal forces are the most likely cause both with and without shoulder dystocia.     

Outcomes associated with introduction of a shoulder dystocia protocol

The objective of this study was to assess outcomes that are associated with the implementation of a shoulder dystocia protocol that is focused on team response. We identified women who had a shoulder dystocia during 3 time periods: 6 months before (period A), 6 months during (period B), and 6 months after (period C) the institution of a shoulder dystocia protocol. Documentation and health outcomes were compared among the time periods. During the study period, 254 women (77, 100, and 77 in periods A, B, and C, respectively) had a shoulder dystocia. There were no differences among study periods in patient characteristics. However, complete and consistent documentation increased (14% to 50% to 92%; P < .001), and brachial plexus palsy that was diagnosed at delivery (10.1% to 4.0% to 2.6%; P = .03) and at neonatal discharge (7.6% to 3.0% to 1.3%; P = .04) declined.     

Catastrophic shoulder dystocia.

OBJECTIVE: The objective of this paper is to outline in a stepwise fashion a life-saving management sequence for catastrophic shoulder dystocia. METHOD: Five cases of catastrophic shoulder dystocia are analyzed to determine optimal management when confronted with this terrifying obstetric complication. RESULT: The management of these five cases reveals the importance of the early use of uterine relaxing agents and general anesthesia. A second physician is also ideal. The absence of a nuchal cord may result in more favorable outcomes. CONCLUSION: The key to achieving improved outcomes when confronted with catastrophic shoulder dystocia include (1) immediate availability of an operating room and anesthesia personnel, (2) the willingness to use uterine relaxing agents, (3) the availability of a second physician, (4) an understanding of the best sequence of remedial measures to follow, (5) total delivery within 12-13 min of the delivery of the head (almost impossible when the delivery process begins in a birthing room) and (6) a cesarean room should be considered for delivery of all massively obese women.     

Antenatal and intrapartum prediction of shoulder dystocia

Objectives

To (1) develop algorithms to calculate the risk of shoulder dystocia at individual deliveries; (2) evaluate screening for shoulder dystocia.

Study design

Retrospective analysis of 40284 consecutive term cephalic singleton pregnancies using a ‘train and test’ method. Four models were derived using logistic regression and tested (birthweight alone; birthweight and other independent antenatal variables; birthweight and all independent antenatal and intrapartum variables; and all independent variables excluding birthweight).

Results

Shoulder dystocia occurred in 240 deliveries (0.6%). Birthweight was the most important risk factor although 98 cases (41%) occurred in babies weighing <4.0 kg. Birthweight and maternal height were the only independent antenatal variables; for intrapartum use, only these and instrumental delivery were independent. The antenatal model could calculate an individual's risk; the intrapartum model could also calculate the risk if an instrumental delivery were undertaken. Both showed 0.7% women to have a risk of shoulder dystocia of >10%. Although the antenatal model had high predictability (area under curve 0.89), it was no better than birthweight alone and had a sensitivity of 52.4%. Where birthweight was excluded, prediction of shoulder dystocia was poor.

Conclusion

Antepartum and labour calculation of the risk of shoulder dystocia is possible. Whilst greatly hindered by the inaccuracy of estimating weight, it allows due weight to be given to factors which may already be influencing clinical practice. However, shoulder dystocia cannot be predicted with sufficient accuracy to allow universal screening.     

Obstetric maneuvers for shoulder dystocia and associated fetal morbidity

OBJECTIVE: We sought to determine the fetal injury rate associated with shoulder dystocia and to determine whether there is a higher rate of brachial plexus injury or bone fracture when fetal manipulation techniques are required for delivery. STUDY DESIGN: A retrospective review of 285 cases of shoulder dystocia that occurred between January 1991 and December 1995 was performed. The type, sequence, and combination of obstetric maneuvers used to relieve the shoulder dystocia were noted. These cases were divided into two groups, as follows: (1) those resolved with McRoberts' maneuver, suprapubic pressure, or proctoepisiotomy or a combination of these and (2) those that required the addition of direct fetal manipulative maneuvers (Woods, posterior arm, or Zavanelli). Fetal injury was defined as the occurrence of brachial plexus palsy, clavicular fracture, humeral fracture, or fetal death caused by asphyxial complications. RESULTS: The fetal injury rate was 24.9% (71/285), including 48 (16.8%) brachial plexus palsies, 27 (9.5%) clavicular fractures, and 12 (4.2%) humeral fractures. Sixteen infants had both nerve injury and bone fracture. Four (8.9%) brachial plexus palsies had documented persistence at 1 year of follow-up. One neonatal death occurred at age 3 months after an episode of hypoxic ischemic encephalopathy. The incidence of bone fracture was not higher when direct fetal manipulation was required: 21 of 127 (16.5%) versus 18 of 158 (11.4%), p = 0.21. The incidence of brachial plexus palsy was also similar in both groups (27/127 vs 21/158, p = 0.1). CONCLUSIONS: Direct fetal manipulation techniques used to alleviate shoulder dystocia are not associated with an increased rate of bone fracture or brachial plexus injury. (Am J Obstet Gynecol 1998;178:1126-30.)     

The sequential effect of computerized delivery charting and simulation training on shoulder dystocia documentation

Objective.?To estimate the effects of computerized charting and shoulder dystocia (SD) simulation drills on the documentation of SD.

Methods.?180 cases of SD were evaluated in three consecutive time periods: T1: 45 written delivery notes; T2: 48 delivery notes after the implementation of a standardized SD note in the computerized medical record; T3: 87 computerized delivery notes after SD simulation drills.

Results.?A standardized SD computerized note resulted in a significant improvement in documentation of EFW, diabetic status, time of the body delivery, fetal head position, which shoulder was impacted, anesthesia, the length of each stage of labor, NICU admission, the birth weight, and that a discussion took place with the patient. The implementation of a SD simulation drill was associated with a further increase in the documentation of the instruments used for delivery, whether a cord pH was performed, and that a discussion took place with the patient. Additionally, the implementation of a SD simulation drill increased the rate of documented SD (1.61% vs. 2.37% of vaginal deliveries, p?=?0.0275) and the number of obstetricians who documented a SD (32.35% vs. 60.29% of delivering obstetricians, p?=?0.0020).

Conclusions.?Standardized SD notes as well as simulation drills improve documentation of SD events.     

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.