Shoulder dystocia and brachial plexus injury: a case-control study

Maternal and neonatal complications of shoulder dystocia with a focus on obstetric maneuvers: A case-control study of 1103 deliveries

INTRODUCTION

Shoulder dystocia is a severe obstetric emergency that can cause substantial neonatal and maternal complications. This study aims to assess the performed obstetric maneuvers and their frequency, success, and association with maternal and neonatal complication rates.

MATERIAL AND METHODS

The study population was collected among all deliveries in the Hospital District of Helsinki and Uusimaa between 2006 and 2015 (n = 181 352) by searching for ICD-10 codes for shoulder dystocia, brachial plexus injury and clavicle fracture. Shoulder dystocia cases (n = 537) were identified by reviewing the medical records. Shoulder dystocia cases treated with one or two maneuvers were compared with those treated with at least three. Medical records of a matched control group constituting of 566 parturients without any of the forementioned ICD-10 codes were also scrutinized.

RESULTS

Using the four most common obstetric maneuvers (McRoberts maneuver, suprapubic pressure, rotational maneuvers, the delivery of the posterior arm) significantly increased during the study period with individual success rates of 61.0%, 71.9%, 68.1% and 84.8%, respectively. Concurrently, the rate of brachial plexus injury and combined neonatal morbidity significantly declined from 50% to 24.2% (p = 0.02) and from 91.4% to 48.5% (p < 0.001). Approximately 75% of shoulder dystocia cases treated with maneuvers were resolved by the McRoberts maneuver and/or suprapubic pressure, but each of the four most performed maneuvers significantly increased the cumulative success rate individually and statistically (p < 0.001). The rates of brachial plexus injury and combined neonatal morbidity were at their highest (52.9% and 97.8%) when none of the maneuvers were performed and at their lowest when two maneuvers were performed (43.0% and 65.4%). The increasing number (≥3) of maneuvers did not affect the combined maternal or neonatal morbidity or brachial plexus injury but increased the risk for third- or fourth-degree lacerations (odds ratio 2.91, 95% confidence interval 1.17 to 7.24).

CONCLUSIONS

The increased use of obstetric maneuvers during the study period was associated with decreasing rates of neonatal complications; conversely, the lack of obstetric maneuvers was associated with the highest rate of neonatal complications. These emphasize the importance of education, maneuver training and urgently performing shoulder dystocia maneuvers according to the international protocol guidelines.

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).

Population-Based Risk Factors for Shoulder Dystocia

OBJECTIVE

To re-examine the risk factors for shoulder dystocia given the increasing rates of obesity and diabetes in pregnant women.

DESIGN

Retrospective observational study.

SETTING

Five hospitals located in Wisconsin, Florida, Maryland, Michigan, and Alabama.

PARTICIPANTS

We evaluated 19,236 births that occurred between April 1, 2011, and July 25, 2013.

METHODS

Data were collected from electronic medical records and used to evaluate the risk of shoulder dystocia. Data were analyzed using a generalized linear mixed model, which controlled for clustering due to site.

RESULTS

When insulin was prescribed, gestational diabetes was associated with an increased risk of shoulder dystocia (odds ratio = 2.10, 95% confidence interval [1.01, 4.37]); however, no similar association was found with regard to gestational diabetes treated with glycemic agents or through diet. Use of epidural anesthesia was associated with an increased risk for shoulder dystocia (odds ratio = 3.47, 95% confidence interval [2.72, 4.42]). Being Black or Hispanic, being covered by Medicaid or having no insurance, infant gestational age of 41 weeks or greater, and chronic diabetes were other significant risk factors.

CONCLUSION

With the changing characteristics of pregnant women, labor and birth clinicians care for more pregnant women who have an increased risk for shoulder dystocia. Our findings may help prospectively identify women with the greatest risk.

Characteristics and outcome of brachial plexus birth palsy in neonates

AIM

To relate pregnancy characteristics to extent and reversibility of brachial plexus birth palsy (BPBP) in neonates.

METHODS

Retrospective case-control study: newborns with a registered diagnosis of BPBP (n = 168) 1990-2005 were compared to data from a randomly selected control group (n = 1000). Characteristics were related to the level of injury, reversibility and outcome.

RESULTS

Among 51,841 newborns, 168 cases with BPBP were found (incidence 3.2/1000 newborns/year). Extent and reversibility of lesion did not differ with respect to characteristics of mothers, foetuses or deliveries. Children with C5-C6 and C5-C6-C7 injuries had complete recovery in 86% and 38%, respectively. Global injuries (C5-Th1) always had permanent disability. Accelerators (foetal weight gain >35 g/day after 32 weeks of gestation) and foetuses with estimated weight deviation ≥ +22% at 32 weeks were at seven- and ninefold increased risk of BPBP. Parous women were at doubled risk as compared to nulliparous women.

CONCLUSION

Maternal and foetal characteristics influence risk of BPBP, but not the extent of injury or reversibility of injury. Because of the high risk of permanent disability and modest risk of low Apgar or pH among newborns with BPBP, the recommendation of prompt delivery may need to be re-evaluated.

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.

Etiological risk factors for brachial plexus palsy

AIM

To investigate risk factors for brachial plexus palsy in newborns. We analyzed 45 544 live-born children, born over a nine-year period from January 1, 1996 to December 31, 2004.

METHODS

The analysis was retrospective and based on the medical documentation of the Clinic for Gynecology and Obstetrics, Clinic for Neurology, and Clinic for Physical Medicine and Rehabilitation of the University Clinical Center Tuzla. We compared study and control groups of newborns. Rates among groups were compared using Chi-square, with significance at p < 0.05, and with significance at p < 0.01.

RESULTS

Examining epidemiological characteristics, 86 newborns with brachial plexus palsy had been recorded, thus, the prevalence was 1.86 per 1000 live-born children. Analyzing maternal and neonatal factors, and the labor pattern itself, it was found that the highest factors of risk for brachial plexus injury were birth weight of over 4000 g, a precipitous second stage of labor (<15 minutes), and vacuum-extractor assisted labor. Brachial plexus palsy was more frequent when the mothers were overweight, with a body mass index >or=29 kg/m2. None of the parturient women, whose newborns were diagnosed with brachial plexus palsy, had external conjugate diameter <18 cm. Newborns delivered vaginally were not diagnosed with a higher frequency of brachial plexus palsy when compared to newborns who were delivered by cesarean section, but newborns who were vaginal breech-delivered were diagnosed to have a higher incidence of brachial plexus palsy. Newborns whose mothers were older than 35 years were diagnosed to have brachial plexus palsy more frequently, but a statistically significant difference between primiparas and multiparas was not found. A total of 39 newborns (45.2%) were diagnosed with a fracture of the clavicle, which was the most frequently combined damage with brachial plexus injury. Forty-two newborns (48.8%) had an Apgar score of <or=7 in the first minute after delivery, which indicates intrapartal fetal distress and is an indication of the traumatic nature of these deliveries. The average birth weight of newborns with brachial plexus damage was 3858.1+/-587.7 g, which for an average gestational age of 38.8+/-1.8 weeks, corresponds to eutrophic newborns. Both male and female newborns were diagnosed to have brachial plexus palsy comparably frequently, and almost all deliveries (97.7%) were initiated spontaneously. The majority of newborns were born between the hours of 02:00 and 03:00 and between the hours of 14:00-15:00.

An approach to the prediction of neonatal Erb palsy

We devised a method to predict risk of neonatal Erb palsy using variables ascertainable before delivery. Multiple logistic regression modeling was used to construct an Erb palsy risk score from a case-control study of 45 consecutive Erb palsy cases and 90 controls. Receiver-operator characteristics identified a range of scores for which likelihood ratios were determined for calculation of predictive values across a range of prior probabilities. In the final model, large estimated fetal weight, gestational diabetes, large maternal body mass index, large weight gain, and black race were associated with 2.3-4.8 times greater odds of Erb palsy. A long second stage had a modest effect on the odds (OR=2.7, P=0.13), unless preceded by a long deceleration phase, which combination increased the odds of Erb palsy to 20.1 (P=0.001). A risk score of 0.72 had a sensitivity of 36% and a specificity of 99%. In a theoretical population with a birth prevalence of brachial plexus palsy of 2.5/1000, application of the risk score would prevent 36% of cases and result in about 14 cesareans for every nerve injury prevented. We conclude that risk scoring using multiple logistic regression coefficients of variables that can be known in time to affect decision-making about mode of delivery has the potential to guide intervention to prevent some Erb palsies.

Experience of shoulder dystocia in a district general hospital: what have we learnt?

Shoulder dystocia is an obstetric emergency that currently affects 0.6% of all deliveries in the UK. This potentially serious obstetric emergency requires early recognition and prompt involvement of appropriately trained personnel to deliver the baby safely and without delay. Failure to do so may result in significant neonatal and maternal morbidity, with ensuing litigation. As part of clinical governance, hospital trusts are under pressure to continually improve the quality of service provided to their patients. Meticulous and accurate documentation is the crucial first step. The second step is preparedness and practice. Although we are still not very good at being able to prevent or predict shoulder dystocia, when it occurs, we must be ready and able to deal with it effectively. This can best be accomplished through re-education and re-training of obstetric staff and the updating of Trust management protocols. By promptly acting in accordance with established evidence-based guidelines, we will improve our ability to carefully and competently manage deliveries complicated by shoulder dystocia. However, failing to do so will inevitably have dire repercussions for all.

Risk factors for recurrent shoulder dystocia, Washington state, 1987-2004

OBJECTIVE

The objective of the study was to identify recurrent shoulder dystocia risk factors.

STUDY DESIGN

This was a population-based case-control study in Washington state (1987-2004). Primary and recurrent shoulder dystocia incidences were calculated. Logistic regression was used to calculate adjusted odds ratios (aORs) and 95% confidence intervals (CIs) for subsequent shoulder dystocia risk factors.

RESULTS

Primary and recurrent shoulder dystocia annual incidences were 2.3 of 100 and 13.5 of 100. Of 26,208 women with shoulder dystocia deliveries, 8991 had subsequent vaginal births, and of those, 1060 (11.8%) had a recurrent shoulder dystocia. Index pregnancy birthweight was associated with an increased risk of subsequent shoulder dystocia: 3500-3999 g, aOR 1.8 (95% CI 1.5 to 2.3); 4000-4499 g, aOR 3.3 (95% CI 2.6 to 4.1); 4500-4999 g, aOR 3.1 (95% CI 2.3 to 4.3); and 5000 g or greater, aOR 3.8 (95% CI 2.0 to 7.3). Vacuum delivery, aOR 1.4 (95% CI 1.2 to 1.7), and severe shoulder dystocia, aOR 2.1 (95% CI 1.6 to 2.7) in the index delivery, were also significant.

CONCLUSION

Birthweight of 3500 g or greater, vacuum delivery, or severe shoulder dystocia in the index delivery were independent risk factors for shoulder dystocia recurrence.

Fetal trauma in term pregnancy

OBJECTIVE

The objective of the study was to determine the incidence and type of fetal trauma in term pregnancy in relation to method of delivery, maternal age, parity, and birthweight.

STUDY DESIGN

From the Nova Scotia Atlee Perinatal Database, fetal trauma was evaluated in all term (37 weeks or longer) singleton fetuses without major anomaly in vertex presentation over a 14-year period (1988-2001).

RESULTS

The overall risk of fetal trauma was low (2.0%); that of major fetal trauma was 0.16%. Major and minor fetal trauma was significantly increased with labor, compared with no labor (adjusted relative risks [RRs], 9.59; 95% confidence interval [CI], 1.34-68.47, and RR, 11.25; 95% CI, 5.05-25.09, respectively). Cesarean delivery was protective for major and minor fetal trauma, compared with vaginal delivery (adjusted RRs, 0.21; 95% CI, 0.12-0.40, and RR, 0.46; 95% CI, 0.39-0.54, respectively).

CONCLUSION

The risk of significant fetal trauma in term pregnancy is very low and most likely to be associated with labor and with assisted vaginal delivery.

Fatal birth trauma due to an undiagnosed abdominal teratoma: case report and review of the literature

The fetus is subjected to mechanical forces during labor and delivery, which may result in traumatic injuries. Such injuries include intracranial hemorrhage, spinal cord lesions, cephalhematoma, cranial or peripheral nerve palsies, intraabdominal organ rupture, or bony fractures. Risk for perinatal trauma and mortality is increased in primigravidas, multiple gestations, abnormal presentations, maternal-fetal disproportion, oligohydramnios, forceps or vacuum extractions, and internal version maneuvers. Very-low-birth-weight neonates (<1500 g) are at high risk due to ease of deformity of the cranium. Infants with certain congenital anomalies or pathologic processes that distort normal anatomy are also at increased risk, especially when a prenatal diagnosis is lacking. The authors present a case of a term gestation neonate who sustained a cervical spine dislocation fracture of C5-7, with subtotal transection of the spinal cord and resultant paralysis. The fetus was in vertex presentation, and a manual vaginal delivery was attempted. When the infant lodged in the birth canal following a difficult delivery of the head and arms, its enlarged abdomen was palpated, and the delivery was converted to an emergent cesarean section. The infant lived for 3 days and then expired due to neurologic complications of trauma sustained during the attempted vaginal delivery. Autopsy revealed a previously undiagnosed intraabdominal immature teratoma. The pathology of teratomas, the most common neonatal tumor and occasionally implicated in cases of birth trauma, will be addressed, followed by a review of the literature concerning birth trauma.

Shoulder dystocia and injuries: prevention and management

PURPOSE OF REVIEW

Shoulder dystocia is an obstetric emergency that is often unpredictable and unanticipated. Despite the identification of various clinical risk factors, our ability to predict and prevent shoulder dystocia is very limited. Effective and timely clinical management is essential to offer the best chance of a satisfactory outcome.

RECENT FINDINGS

Upon diagnosis of the condition, a team working in tandem to resolve the problem is very effective. Use of the McRoberts maneuver, application of suprapubic pressure, with an adequate episiotomy allow resolution of over 50% of cases, with a low risk of fetal injury. Secondary maneuvers include rotation of the shoulders and delivery of the posterior shoulder. These are technically more challenging and may be associated with a higher risk of fetal injury. More drastic action may be considered in dire cases where even secondary maneuvers fail. These include the Zavanelli maneuver, symphysiotomy or iatrogenic clavicular fracture. These techniques, while seldom required, may be lifesaving in extremely severe cases.

SUMMARY

Upon resolution of the clinical event, it is essential to document the entire event, and to discuss the clinical problem and management with the parents. These actions will reduce the risk of medical litigation, and improve patient satisfaction with clinical care.

What factors are associated with neonatal injury following shoulder dystocia?

OBJECTIVE

To identify factors associated with the development of neonatal injury in the setting of shoulder dystocia.

STUDY DESIGN

Medical record ICD-9 codes and a computerized perinatal database were reviewed to identify cases of shoulder dystocia from January 1996 to January 2001 in a tertiary care center. For confirmation of the diagnosis and collection of data, both maternal and neonatal charts were then reviewed and neonatal injuries categorized as either neurological (brachial plexus injury) or skeletal (clavicular fracture, humeral fracture). Shoulder dystocia cases were divided into groups based on the presence of neonatal injury at delivery or at discharge (with or without Erb's palsy). The group with neonatal injury was compared for demographic and obstetrical factors to the group without injury (control). chi (2) test, Mann-Whitney test and logistic regression were used as appropriate.

RESULTS

During this 5-year period, there were 25,995 deliveries and 206 (0.8%) confirmed cases of shoulder dystocia. Of these cases, 36 (17.5%) had neonatal injury diagnosed at delivery and 25 (12%) remained with significant residual injury at discharge. Of these there were 19 cases of Erb's palsy and six cases of clavicular fracture. No association was found between neonatal injury and maternal age, ethnicity, diabetes, operative vaginal delivery or number of obstetrical maneuvers. However, maternal body mass index >30 kg/m2, a second stage of labor >20 min and a birth weight >4500 g were all associated with an increased risk of neonatal injury at delivery and at discharge, including Erb's palsy. After logistic regression analysis, only a second stage of delivery >20 min remained significantly associated with neonatal injury at discharge.

CONCLUSION

In our population, maternal obesity was associated with an increased risk of neonatal injury after shoulder dystocia. In addition, a short second stage of labor (<20 min) was associated with a lower rate of neonatal injury.

Part 1: early recognition and treatment of birth trauma: injuries to the head and face

The Joint Commission on Accreditation of Healthcare Organizations (JCAHO) Sentinel Event Alert from July 21, 2004 states that there have been 47 cases of birth trauma-related perinatal death or permanent disability reported for JCAHO review since 1996. This report clearly illustrates the importance of birth trauma in clinical practice for neonatal and perinatal nurses. Estimates suggest that birth trauma occurs in 2% to 7% of all deliveries and is associated with an increase in both mortality and morbidity. Birth trauma to the head may result in minor superficial extracranial injuries, such as caput succedaneum and cephalohematoma, or more serious and potentially life threatening lesions such as subgaleal hemorrhages. The potential for deeper intracranial injury, such as subarachnoid or subdural hemorrhage exists; these may be isolated or associated with skull fractures and/or other extracranial injuries. Injury to the eye, nasal structures, and paralysis of the vocal cords may also result from birth trauma during a difficulty delivery. Part 1 of this 2-part article will focus on birth injuries to the head and face. Part 2 of the series will review more systemic birth injuries that may involve abdominal organs, the spine and skeletal system, and peripheral and facial nerves.

Temporary Erb-Duchenne Palsy Without Shoulder Dystocia or Traction to the Fetal Head

BACKGROUND

Although many retrospective studies report that brachial plexus palsies occur after vaginal delivery in the absence of recorded shoulder dystocia, there are no known prospective reports by a treating clinician (PubMed, English language only, 1952-June 2004, search terms: shoulder dystocia, nonshoulder dystocia, obstetric brachial plexus injury, Erb's palsy, Erb-Duchenne palsy, spontaneous vaginal delivery).

CASE

A multiparous patient presented with a birth plan requesting that the baby be allowed to deliver on its own, without traction on the head and without suctioning. Although induced at term for elevated blood pressure, the otherwise healthy patient experienced a normal labor with a 30-minute second stage. At delivery, which was videotaped by the father, the fetal head presented over an intact perineum in a right-occiput-anterior position. Without traction, the anterior shoulder delivered spontaneously with the next contraction and Valsalva, followed by the posterior shoulder. The trunk followed routinely. The average-weight for gestational age neonate exhibited an Erb-Duchenne palsy of the right (posterior) arm that resolved on the fourth day of life.

CONCLUSION

Temporary Erb-Duchenne palsy can occur in the posterior arm after normal labor and spontaneous delivery without shoulder dystocia or traction on the fetal head.

Effect of epidural anaesthesia on clinician-applied force during vaginal delivery

OBJECTIVE

Epidural anesthesia (EA) is used in 80% of vaginal deliveries and is linked to neonatal and maternal trauma. Our objectives were to determine (1) whether EA affected clinician-applied force on the fetus and (2) whether this force influenced perineal trauma.

STUDY DESIGN

After informed consent, multiparas with term, cephalic, singletons were delivered by 1 physician wearing a sensor-equipped glove to record force exerted on the fetal head. Those with EA were compared with those without for delivery force parameters. Regression analysis was used to identify predictors of vaginal laceration.

RESULTS

The force required for delivery was greater in patients with EA (n = 27) than without (n = 5) (P < .01). Clinical parameters, including birth weight (P = .31) were similar between the groups. Clinician force was similar in those with no versus first- versus second-degree laceration (P = .5). Only birth weight was predictive of laceration (P = .02).

CONCLUSION

Epidural use resulted in greater clinician force required for vaginal delivery of the fetus in multiparas, but this force was not associated with perineal trauma.