Are labor abnormalities more common in shoulder dystocia?

A critical evaluation of the external and internal maneuvers for resolution of shoulder dystocia

In the management of shoulder dystocia, it is often recommended to start with external maneuvers, such as the McRoberts maneuver and suprapubic pressure, followed by internal maneuvers including rotation and posterior arm delivery. However, this sequence is not based on scientific evidence of its success rates, the technical simplicity, or the related complication rates. Hence, this review critically evaluates the success rate, technique, and safety of different maneuvers. Retrospective reviews showed that posterior arm delivery has consistently higher success rates (86.1%) than rotational methods (62.4%) and external maneuvers (56.0%). McRoberts maneuver was thought to be a simple method, however, its mechanism is not clear. Furthermore, McRoberts position still requires subsequent traction on the fetal neck, which presents a risk for brachial plexus injury. The 2 internal maneuvers have anatomic rationales with the aim of rotating the shoulders to the wider oblique pelvic dimension or reducing the shoulder width. The techniques are not more sophisticated and requires the accoucher to insert the correct hand (according to fetal face direction) through the more spacious sacro-posterior region and deep enough to reach the fetal chest or posterior forearm. The performance of rotation and posterior arm delivery can also be integrated and performed using the same hand. Retrospective studies may give a biased view that the internal maneuvers are riskier. First, a less severely impacted shoulder dystocia is more likely to have been managed by external maneuvers, subjecting more difficult cases to internal maneuvers. Second, neonatal injuries were not necessarily caused by the internal maneuvers that led to delivery but could have been caused by the preceding unsuccessful external maneuvers. The procedural safety is not primarily related to the nature of the maneuvers, but to how properly these maneuvers are performed. When all these maneuvers have failed, it is important to consider the reasons for failure otherwise repetition of the maneuver cycle is just a random trial and error. If the posterior axilla is just above the pelvic outlet and reachable, posterior axilla traction using either the accoucher fingers or a sling is a feasible alternative. Its mechanism is not just outward traction but also rotation of the shoulders to the wider oblique pelvic dimension. If the posterior axilla is at a higher sacral level, a sling may be formed with the assistance of a long right-angle forceps, otherwise, more invasive methods such as Zavanelli maneuver, abdominal rescue, or symphysiotomy are the last resorts.

Shoulder dystocia: Updating some medico-legal issues

Shoulder dystocia, or shoulder entrapment at birth, is an obstetrician's nightmare, which not infrequently leads to court litigation with complaints of serious foetal and/or maternal damage. Increasingly, retrospective management scrutiny is extending well beyond second stage birth mechanics and involving all case file entries, history taking, ultrasound scan measurements and haematology profile results, etc. The article highlights some medico-legal issues including the influence of the Montgomery ruling on patient disclosure and subsequent management.

Assessment of the impact of an expectant management in case of abnormally progressing first-stage labor

OBJECTIVE

To compare the cesarean section rate before and after the introduction of an expectant management protocol in patients with abnormally progressing first-stage labor.

METHODS

A prospective monocentric cohort study performed between January 2012 and July 2016.

RESULTS

267 patients were included, 97 in the control group and 170 in the study group. The number of cesarean sections decreased from 86 % to 45 % (p < 0.001). The number of instrumental extractions increased from 8.3% to 29.4% (p < 0.001). The number of postpartum hemorrhages increased from 5.2% to 18% (p < 0.01). No differences in the rates of perineal lesions, neonatal pHa below 7.10, and shoulder dystocia were observed.

CONCLUSION

The expectant management in patients with labor arrest in the first stage was associated with a decrease in the number of cesarean sections, at the cost of an increase in instrumental extractions and postpartum hemorrhages.

Pathophysiologic Origins of Brachial Plexus Injury

OBJECTIVE

To analyze the origins and consequences of cases of brachial plexus injuries and their relationship to shoulder dystocia.

METHODS

We conducted a retrospective cohort study and identified all neonates with brachial plexus injury delivered at our institution between March 2012 and July 2019. A review was performed of the maternal and neonatal records of each neonate to identify obstetric antecedents, including the occurrence of shoulder dystocia and persistence of the injury. Experience of the delivering clinician was also examined. Statistical analysis was performed with the Fisher exact test, χ test for trends, and two-tailed t tests.

RESULTS

Thirty-three cases of brachial plexus injury were identified in 41,525 deliveries (0.08%). Fourteen (42%) of these cases were not associated with shoulder dystocia; three (9%) followed cesarean delivery. Brachial plexus injury without shoulder dystocia was related to the absence of maternal diabetes, lower birth weights, and a longer second stage of labor. Persistent brachial plexus injury at the time of discharge was seen with equal frequency among neonates with (17/19, 89%, 95% CI 0.52-100%) and without shoulder dystocia (10/14, 71%, 95% CI 34-100%), P=.36). Whether brachial plexus injury was transient or persistent after shoulder dystocia was unrelated to the years of experience of the delivering clinician. Despite ongoing training and simulation, the already low incidence of brachial plexus injury did not decrease over time at our institution.

CONCLUSION

Brachial plexus injury and shoulder dystocia represent two complications of uterine forces driving a fetus through the maternal pelvis in the presence of disproportion between the passage and the shoulder girdle of the passenger. Either or both of these complications may occur, but often are not causally related.

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).

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.

Impact of shoulder dystocia, stratified by type of manoeuvre, on severe neonatal outcome and maternal morbidity

BACKGROUND

Shoulder dystocia is an uncommon and unpredictable obstetric emergency. It is associated with significant neonatal, maternal and medico-legal consequences.

AIM

To ascertain the impact shoulder dystocia has on severe neonatal and maternal outcomes specific to the type of manoeuvre.

MATERIALS AND METHODS

This was a retrospective study of 48 021 term singleton vaginal deliveries the Mater Mothers' Hospital in Brisbane between 2007 and 2015. Maternal and neonatal outcomes were compared between deliveries complicated by shoulder dystocia and those uncomplicated.

RESULTS

Deliveries complicated by shoulder dystocia are associated with low Apgar scores (≤3) at five minutes (odds ratio (OR) 5.25, 95% CI 3.23-8.56, P < 0.001), acidosis (OR 3.10, 95% CI 2.76-3.50, P < 0.001), postpartum haemorrhage (OR 2.28, 95% CI 1.90-2.75, P < 0.001) and perineal trauma (OR 1.92, 95% CI 1.54-2.39, P < 0.001). Compared to McRoberts' manoeuvre and suprapubic pressure alone, the odds of serious neonatal outcome are increased with internal rotational manoeuvres (OR 3.82, 95% CI 2.54-5.74, P < 0.001) and delivery of the posterior arm (OR 4.49, 95% CI 3.54-5.69, P < 0.001). The OR of maternal injury is 2.07 (95% CI 1.77-2.45, P < 0.001), 2.26 (95% CI 1.21-4.21, P < 0.001) and 2.29 (95% CI 1.58-3.32, P < 0.001) with McRoberts'/suprapubic pressure, internal rotation and posterior arm delivery, respectively. Brachial plexus injuries and fractures complicate 1.4 and 0.9% of deliveries, with the risk of injury increasing when greater than one manoeuvre is required.

CONCLUSION

The risk of neonatal and maternal trauma is strongly associated with the number and types of manoeuvres. Given the associated implications, adequate antenatal counselling, simulation training and enhanced labour surveillance are essential.

Predictors of shoulder dystocia at the time of operative vaginal delivery

BACKGROUND

It remains uncertain whether clinical factors known prior to delivery can predict which women are more likely to experience shoulder dystocia in the setting of operative vaginal delivery.

OBJECTIVE

We sought to identify whether shoulder dystocia can be accurately predicted among women undergoing an operative vaginal delivery.

STUDY DESIGN

This was a case-control study of women undergoing a low or outlet operative vaginal delivery from 2005 through 2014 in a single tertiary care center. Cases were defined as women who experienced a shoulder dystocia at the time of operative vaginal delivery. Controls consisted of women without a shoulder dystocia at the time of operative vaginal delivery. Variables previously identified to be associated with shoulder dystocia that could be known prior to delivery were abstracted from the medical records. Bivariable analyses and multivariable logistic regression were used to identify factors independently associated with shoulder dystocia. A receiver operating characteristic curve was created to evaluate the predictive value of the model for shoulder dystocia.

RESULTS

Of the 4080 women who met inclusion criteria, shoulder dystocia occurred in 162 (4.0%) women. In bivariable analysis, maternal age, parity, body mass index, diabetes, chorioamnionitis, arrest disorder as an indication for an operative vaginal delivery, vacuum use, and estimated fetal weight >4 kg were significantly associated with shoulder dystocia. In multivariable analysis, parity, diabetes, chorioamnionitis, arrest disorder as an indication for operative vaginal delivery, vacuum use, and estimated fetal weight >4 kg remained independently associated with shoulder dystocia. The area under the curve for the generated receiver operating characteristic curve was 0.73 (95% confidence interval, 0.69-0.77), demonstrating only a modest ability to predict shoulder dystocia before performing an operative vaginal delivery.

CONCLUSION

While risk factors for shoulder dystocia at the time of operative vaginal delivery can be identified, reliable prediction of shoulder dystocia in this setting cannot be attained.

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.

Caregiver's satisfaction with a video tutorial for shoulder dystocia management algorithm

In our questionnaire, a video tutorial illustrating the management of shoulder dystocia was considered by health personnel as a useful complementary training tool. We prepared a 5-min video tutorial on the management of shoulder dystocia, using a simulator that includes maternal pelvic and baby models. We performed a survey among obstetric personnel in order to assess their opinion on the tutorial by inviting them to watch the video tutorial and answer an online questionnaire. Five multiple-choice questions were set, focusing on the video's main objectives: clarity, simplicity and usefulness. Following the collection of answers, global and category-weighted analyses were conducted for each question. Out of 956 invitations sent, 482 (50.4%) answered the survey. More than 90% of all categories found the video tutorial to be clinically relevant and clear. For revising the management of shoulder dystocia most obstetric personnel would use the video tutorial together with traditional textbooks. In conclusion, our video tutorial was considered by health personnel as a useful complementary training tool.

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. The majority of shoulder dystocia cases occur without major risk factors. Moreover, even the best antenatal predictors have a low positive predictive value. Shoulder dystocia therefore cannot be reliably predicted, and the only preventative measure is cesarean delivery.

Risk factors for neonatal brachial plexus palsy

Neonatal brachial plexus palsy (NBPP) is an unpredictable complication of childbirth. Historic risk factors for the occurrence of NBPP have included shoulder dystocia, fetal macrosomia, labor abnormalities, operative vaginal delivery, and prior NBPP. However, whether studied alone or in combination, these risk factors have not been shown to be reliable predictors. The majority of NBPP cases occur in women with infants <4500 g who are not diabetic and have no other identifiable risk factors. Furthermore, cesarean section reduces but does not completely eliminate the risk for NBPP. In this section, the relationship of these historic obstetric risk factors to the occurrence of NBPP is further explored.

Diagnosis and treatment of hyperglycemia in pregnancy

Hyperglycemia in pregnancy is an opportunity for women at risk for complications during pregnancy and beyond to change their life course to improve outcomes for themselves and their offspring. Providers of diabetes care during pregnancy complicated by hyperglycemia in pregnancy have the unique opportunity to make a significant difference.

Shoulder Dystocia: Etiology, Common Risk Factors, and Management

Shoulder dystocia and brachial plexus injury occur in 0.5% to 1.5% of all births. Risk factors for both include maternal obesity, excessive prenatal weight gain, maternal diabetes, protracted labor, and fetal macrosomia. These factors are involved in only about 50% of births complicated by shoulder dystocia or brachial plexus injury. Shoulder dystocia has a low recurrence rate (9.8%-16.7%), although history of previous shoulder dystocia is the most reliable predictor of occurrence. Brachial plexus injury is the most common morbidity associated with shoulder dystocia, but 50% of newborns who present with this injury were not subject to shoulder dystocia at birth. Most brachial plexus injuries are transient, although 5% to 22% become permanent. Shoulder dystocia followed by permanent brachial plexus injury or mental impairment is one of the leading causes of malpractice allegations. Prompt assessment and management of shoulder dystocia and preparation to maximize the efficiency of shoulder dystocia maneuvers are critical. Documentation of the appropriate use of maneuvers to relieve shoulder dystocia demonstrates standard of care practice, thereby decreasing the potential for successful malpractice allegations.

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.

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.

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.

[Shoulder dystocia: a ten-year descriptive study in a level-III maternity unit]

OBJECTIVE

Shoulder dystocia is one of the most dreadful complications of vaginal deliveries. The aim of this observational study was to evaluate risk factors of dystocia, maternal and neonatal complications and recurrent risk factors.

PATIENTS AND METHODS

Sixty-six cases of shoulder dystocia occurring between January 1998 and August 2008 in our university hospital were identified. Demographic data, labor management, management of the shoulder dystocia and neonatal outcome were recorded.

RESULTS

The incidence of shoulder dystocia was 0.3%. Multiparity, weight gain greater than 12 kg, and post-term delivery were more present in our study group. McRoberts' manoeuver and symphyseal pressure were first realised. Brachial plexus injuries affected 9% of neonates with skeletal fractures in 7.5% of cases. Maternal morbidity was evaluated at about 8%. Twenty per cent had a recurrent shoulder dystocia.

DISCUSSION AND CONCLUSION

Shoulder dystocia is an obstetric emergency which requires a prompt management of trained personnel. Despite the difficulty of being able to prevent shoulder dystocia, training the obstetric staff could probably improve management of shoulder dystocia.

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.

Birth weight of infants after maternal exposure to typical and atypical antipsychotics: prospective comparison study

BACKGROUND

The effects of in utero exposure to atypical antipsychotics on infant birth weight are unknown.

AIMS

To determine whether atypical and typical antipsychotics differ in their effects on birth weight after maternal exposure during pregnancy.

METHOD

Prospective data on gestational age and birth weight collected by the National Teratology Information Service for infants exposed to typical (n=45) and atypical (n=25) antipsychotics was compared with data for a reference group of infants (n=38).

RESULTS

Infants exposed to atypical antipsychotics had a significantly higher incidence of large for gestational age (LGA) than both comparison groups and a mean birth weight significantly heavier than those exposed to typical antipsychotics. In contrast those exposed to typical antipsychotics had a significantly lower mean birth weight and a higher incidence of small for gestational age infants than the reference group.

CONCLUSIONS

In utero exposure to atypical antipsychotic drugs may increase infant birth weight and risk of LGA.

[Severe shoulder dystocia: study of 14 cases treated by Jacquemier's maneuver]

OBJECTIVE

Shoulder dystocia is a dreadful complication of vaginal deliveries since it can be responsible of brachial plexus palsies and even neonatal deaths. Unlike most studies, we defined shoulder dystocia as the enclosing of fetal shoulders above the superior strait (cavity station of 1cm) and situations being resolved only by delivery of the posterior arm (Jacquemier's maneuver). The purpose of this study was to analyze cases of shoulder dystocia in terms of maternal and neonatal complications and to compare risk factors with those identified in the literature.

MATERIAL AND METHODS

We conducted a retrospective study of 14 cases of severe shoulder dystocia (SSD) which occurred at our hospital between January 1995 and January 2007. TSD was diagnosed in the absence of engagement of both fetal shoulders requiring recourse to Jacquemier's maneuver for delivery. Any gestational diabetes, abnormal progression of labour, suspicion or existence of fetal macrosomia, instrumental delivery, and neonatal complications were noted.

RESULTS

The incidence of SSD was around 1 per thousand. Multiparity, weight gain greater than 15kg and gestational diabetes were moderately present in our study group. Only 20% of neonates were macrosomic and 50% had a birth-weight of less than 4000g. In 80% of cases, an instrumental extraction was practised. Brachial plexus injuries affected 20% of neonates, no fracture was observed, one child died following an unresolved SSD.

CONCLUSION

This series shows that the incidence of SSD is rare and difficultly predictable even though identified risk factors exist. However, an instrumental extraction seems frequently associated with SSD and any extraction should take into account the presence of known risk factors. In spite of the severity of our cases of shoulder dystocia, complications found seemed to be similar to those observed in the literature.

Labour characteristics and neonatal Erb's palsy

OBJECTIVE

To determine risk factors for Erb's palsy, with a focus on graphic labour patterns.

DESIGN

A case-control study.

SETTING

New York City.

SAMPLE

A total of 45 consecutive cases of Erb's palsy and 90 controls.

METHODS

Pregnancies and labours of neonatal Erb's palsy cases were compared with 90 controls using univariate and multiple logistic regression analysis.

MAIN OUTCOME MEASURES

Erb's palsy and shoulder dystocia.

RESULTS

Mothers of children with Erb's palsy had a higher term body mass index and more gestational diabetes than those of controls. Even cases without diabetes had higher blood glucose values after a 50-g glucose challenge than did controls. Cases had a higher birthweight and a lower ratio of head-to-thoracic circumference than controls. Shoulder dystocia occurred in 67% of cases and in 2% of controls (P = 0.001). Only 46% of labours had a completely normal dilatation pattern. In a multiple logistic regression model, variables independently associated with brachial plexus injury were long deceleration phase of labour, long second stage, high birthweight, black race, and high neonatal or maternal body mass.

CONCLUSIONS

Erb's palsy was frequently preceded by abnormal labour and shoulder dystocia; however, a substantial proportion of cases occurred after normal labour and delivery. Predictive models will be necessary to determine to what extent careful monitoring of the terminal portion of dilatation and of fetal descent and incorporation of maternal body mass and race (all independent risk factors in this study) will help identify fetuses at risk for brachial plexus palsy.

Intrapartum interventions for preventing shoulder dystocia

BACKGROUND

The early management of shoulder dystocia involves the administration of various manoeuvres which aim to relieve the dystocia by manipulating the fetal shoulders and increasing the functional size of the maternal pelvis.

OBJECTIVES

To assess the effects of prophylactic manoeuvres in preventing shoulder dystocia.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (1 June 2006).

SELECTION CRITERIA

Randomised controlled trials comparing the prophylactic implementation of manoeuvres and maternal positioning with routine or standard care.

DATA COLLECTION AND ANALYSIS

Two review authors independently applied exclusion criteria, assessed trial quality and extracted data.

MAIN RESULTS

Two trials were included; one comparing the McRobert's manoeuvre and suprapubic pressure with no prophylactic manoeuvres in 185 women likely to give birth to a large baby and one trial comparing the use of the McRobert's manoeuvre versus lithotomy positioning in 40 women. We decided not to pool the results of the two trials. One study reported fifteen cases of shoulder dystocia in the therapeutic (control) group compared to five in the prophylactic group (relative risk (RR) 0.44, 95% confidence interval (CI) 0.17 to 1.14) and the other study reported one episode of shoulder dystocia in both prophylactic and lithotomy groups. In the first study, there were significantly more caesarean sections in the prophylactic group and when these were included in the results, significantly fewer instances of shoulder dystocia were seen in the prophylactic group (RR 0.33, 95% CI 0.12 to 0.86). In this study, thirteen women in the control group required therapeutic manoeuvres after delivery of the fetal head compared to three in the treatment group (RR 0.31, 95% CI 0.09 to 1.02). One study reported no birth injuries or low Apgar scores recorded. In the other study, one infant in the control group had a brachial plexus injury (RR 0.44, 95% CI 0.02 to 10.61), and one infant had a five-minute Apgar score less than seven (RR 0.44, 95% CI 0.02 to 10.61).

AUTHORS' CONCLUSIONS

There are no clear findings to support or refute the use of prophylactic manoeuvres to prevent shoulder dystocia, although one study showed an increased rate of caesareans in the prophylactic group. Both included studies failed to address important maternal outcomes such as maternal injury, psychological outcomes and satisfaction with birth. Due to the low incidence of shoulder dystocia, trials with larger sample sizes investigating the use of such manoeuvres are required.

Shoulder dystocia: the unpreventable obstetric emergency with empiric management guidelines

OBJECTIVE

Much of our understanding and knowledge of shoulder dystocia has been blurred by inconsistent and scientific studies that are of limited scientific quality. In an evidence-based format, we sought to answer the following questions: (1) Is shoulder dystocia predictable? (2) Can shoulder dystocia be prevented? (3) When shoulder dystocia does occur, what maneuvers should be performed? and (4) What are the sequelae of shoulder dystocia?

STUDY DESIGN

Electronic databases, including PUBMED and the Cochrane Database, were searched using the key word "shoulder dystocia." We also performed a manual review of articles included in the bibliographies of these selected articles to further define articles for review. Only those articles published in the English language were eligible for inclusion.

RESULTS

There is a significantly increased risk of shoulder dystocia as birth weight linearly increases. From a prospective point of view, however, prepregnancy and antepartum risk factors have exceedingly poor predictive value for the prediction of shoulder dystocia. Late pregnancy ultrasound likewise displays low sensitivity, decreasing accuracy with increasing birth weight, and an overall tendency to overestimate the birth weight. Induction of labor for suspected fetal macrosomia has not been shown to alter the incidence of shoulder dystocia among nondiabetic patients. The concept of prophylactic cesarean delivery as a means to prevent shoulder dystocia and therefore avoid brachial plexus injury has not been supported by either clinical or theoretic data. Although many maneuvers have been described for the successful alleviation of shoulder dystocia, there have been no randomized controlled trials or laboratory experiments that have directly compared these techniques. Despite the introduction of ancillary obstetric maneuvers, such as McRoberts maneuver and a generalized trend towards the avoidance of fundal pressure, it has been shown that the rate of shoulder-dystocia associated brachial plexus palsy has not decreased. The simple occurrence of a shoulder dystocia event before any iatrogenic intervention may be associated with brachial plexus injury.

CONCLUSION

For many years, long-standing opinions based solely on empiric reasoning have dictated our understanding of the detailed aspects of shoulder dystocia prevention and management. Despite its infrequent occurrence, all healthcare providers attending pregnancies must be prepared to handle vaginal deliveries complicated by shoulder dystocia.

The relationship of fetal position and ethnicity with shoulder dystocia and birth injury

OBJECTIVE

The objective of this study was to examine factors associated with the occurrence of shoulder dystocia and subsequent perinatal outcomes.

STUDY DESIGN

We conducted a retrospective cohort study of 29,612 consecutive term, singleton, vertex vaginal deliveries. The primary outcome was reported shoulder dystocia. Fetal position, ethnicity, and their interaction terms were examined along with maternal characteristics, induction and length of labor, operative vaginal delivery, epidural, and birth weight in both bivariate and multivariate analyses.

RESULTS

Among women who met study criteria, 524 (1.8%) experienced a shoulder dystocia. African American women had the highest risk of shoulder dystocia (2.6%), compared with other races/ethnicities (P = .001). Women who delivered in occiput posterior position were noted to have a lower risk for shoulder dystocia (1.1%) as compared with occiput anterior position (1.8%, P = .046). However, in the setting of a shoulder dystocia, a higher risk of brachial plexus injury was observed in neonates delivered in occiput posterior position (adjusted odds ratio 10.4, 95% confidence interval 3.03 to 35.88) by vacuum-assisted vaginal delivery (adjusted odds ratio 3.24, 95% confidence interval 1.37 to 7.67) and neonates weighing 4000 g or more (adjusted odds ratio 2.53, 95% confidence interval 1.09 to 5.85).

CONCLUSION

Overall African American women have an increased risk of shoulder dystocia, but their neonates are not more likely to experience birth injury. Although occiput posterior position has a protective effect for shoulder dystocia, the risk of brachial plexus injury is increased in the setting of a persistent occiput posterior delivery. These factors should be used to consider a patient's prospective risk for shoulder dystocia and associated outcomes.

Determining factors associated with shoulder dystocia: a population-based study

OBJECTIVE

The study was aimed to define obstetric factors associated with shoulder dystocia.

METHODS

A population-based study comparing all singleton, vertex, term deliveries with shoulder dystocia with deliveries without shoulder dystocia was performed. Statistical analysis was done using multiple logistic regression analysis.

RESULTS

Shoulder dystocia complicated 0.2% (n = 245) of all deliveries included in the study (n = 107965). Independent risk factors for shoulder dystocia in a multivariable analysis were birth-weight > or =4000 g (OR = 24.3; 95% CI 18.5-31.8), vacuum delivery (OR = 5.7, 95% CI 3.4-9.5), diabetes mellitus (OR = 1.7, 95% CI 1.2-2.5) and lack of prenatal care (OR = 1.5, 95% CI 1.1-2.3). A significant linear association was found between birth-weight and shoulder dystocia, using the Mantel-Haenszel procedure. Pregnancies complicated with shoulder dystocia had higher rates of third-degree perineal tears as compared to the comparison group (0.8% versus 0.1%; P < 0.001). Similarly, perinatal mortality was higher among newborns delivered after shoulder dystocia as compared to the comparison group (3.7% versus 0.5%; OR = 7.4, 95% CI 3.5-14.9, P < 0.001). In addition, these newborns had higher rates of Apgar scores lower than 7 at 1 and 5 min as compared to newborns delivered without shoulder dystocia (29.7% versus 3.0%; OR = 13.8, 95% CI 10.3-18.4, P < 0.001 and 2.1% versus 0.3%; OR = 7.2, 95% CI 2.8-18.1, P < 0.001, respectively). Combining risk factors such as large for gestational age, diabetes mellitus and vacuum delivery increased the risk for shoulder dystocia to 6.8% (OR = 32.6, 95% CI 10.1-105.8, P < 0.001).

CONCLUSIONS

Independent factors associated with shoulder dystocia were birth-weight > or =4000 g, vacuum delivery, diabetes mellitus and lack of prenatal care.

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.

Treatment of suspected fetal macrosomia: a cost-effectiveness analysis

OBJECTIVE

Treatment of fetal macrosomia presents challenges to practitioners because a potential outcome of shoulder dystocia with permanent brachial plexus injury is costly both to families and to society. Practitioner options include labor induction, elective cesarean delivery, or expectant treatment. We performed a cost-effective analysis to evaluate the treatment strategies that were preferred to prevent the most permanent brachial plexus injuries with the least amount of dollars spent.

STUDY DESIGN

Using decision analysis techniques, we compared 3 strategies for an infant with an estimated fetal weight of 4500 g: labor induction, elective cesarean delivery, and expectant treatment. The following baseline assumptions were made: Probability of shoulder dystocia in vaginal delivery, .145; labor induction, .03; cesarean delivery, .001; probability of plexus injury, .18; probability of permanent injury, .067; probability of cesarean delivery with induction, .35; with expectant treatment, .33; cost of vaginal delivery, dollar 3376; cost of elective cesarean delivery, dollar 5200; cost of cesarean delivery with labor, dollar 6500; lifetime cost of brachial plexus injury, dollar 1,000,000. Sensitivity analyses were performed.

RESULTS

Under baseline assumptions for an infant who weighs 4500 g, expectant treatment is the preferred strategy at a cost of dollar 4014.33 per injury-free child, compared with elective cesarean delivery at a cost of dollar 5212.06 and an induction cost of dollar 5165.08. Sensitivity analyses revealed that, if the incidence of shoulder dystocia and permanent injury remained <10%, expectant treatment is the preferred method.

CONCLUSION

Fetal macrosomia with possible permanent plexus injuries is a concern. Our analysis would suggest that expectant treatment is the most cost-effective approach to this problem.

Obstetric Outcome of Extreme Macrosomia

OBJECTIVE

To determine the effect of extreme macrosomia on perinatal outcome.

METHODS

We conducted a retrospective review of all deliveries with birth weight > or = 5000 g in a tertiary centre from 1986 to 2000 and analyzed the method of delivery and perinatal outcome.

RESULTS

Extreme macrosomia (birth weight > or = 5000 g) was coded in 111 deliveries. There were 62 deliveries by Caesarean section (CS) (25 in labour and 37 elective). The 49 vaginal deliveries were complicated by 10 (20%) cases of shoulder dystocia and 3 (6%) of Erb's palsy. Permanent Erb's palsy was noted in only 1 of these 3 cases. Shoulder dystocia was associated with use of oxytocin and instrumental deliveries.

CONCLUSION

Implementing the 2002 guidelines from the American College of Obstetricians and Gynecologists (that is, recommending Caesarean delivery of fetuses with an estimated weight of at least 5000 g) would have a negligible effect on the CS rate while eliminating 10 cases of shoulder dystocia in 49 births. A policy eliminating the use of oxytocin and instrumental deliveries would have prevented most birth traumas in this group. Unfortunately, this high-risk group is difficult to identify in the antepartum period, complicating the implementation of these guidelines and probably leading to higher rates of CS. In addition, the effect of endorsing such a policy on overall neonatal and maternal morbidity is minimal, because most morbidity occurs in newborns weighing less than 4000 g.

Gender Does Matter in Perinatal Medicine

OBJECTIVE

To investigate complications and outcome of pregnancies with male and female fetuses.

METHODS

A population-based study comparing all singleton deliveries between the years 1988 and 1999 was performed. We compared pregnancies with male vs. female fetuses. Patients with a previous cesarean section (CS) were excluded from the study. Statistical analyses with the Mantel-Haenszel technique and multiple logistic regression models were performed to control for confounders.

RESULTS

During the study period there were 55,891 deliveries of male and 53,104 deliveries of female neonates. Patients carrying male fetuses had higher rates of gestational diabetes mellitus (OR = 1.1; 95% CI 1.01-1.12; p = 0.012), fetal macrosomia (OR = 2.0; 95% CI 1.8-2.1; p < 0.001), failure to progress during the first and second stages of labor (OR = 1.2; 95% CI 1.1-1.3; p < 0.001 and OR = 1.4; 95% CI 1.3-1.5; p < 0.001, respectively), cord prolapse (OR = 1.3; 95% CI 1.1-1.6; p = 0.014), nuchal cord (OR = 1.2; 95% CI 1.1-1.2; p < 0.001) and true umbilical cord knots (OR = 1.5; 95% CI 1.3-1.7; p < 0.001). Higher rates of CS were found among male compared with female neonates (8.7 vs. 7.9%; OR = 1.1; 95% CI 1.06-1.16; p < 0.001). Using three multivariate logistic regression models and controlling for birth weight and gestational age, male gender was significantly associated with non-reassuring fetal heart rate patterns (OR = 1.5; 95% CI 1.4-1.6; p < 0.001), low Apgar scores at 5 min (OR = 1.5; 95% CI 1.3-1.8; p < 0.001) and CS (OR = 1.2; 95%CI 1.2-1.3; p < 0.001). Controlling for possible confounders like gestational diabetes, cord prolapse, failed induction, nonprogressive labor, fetal macrosomia, nuchal cord and true umbilical cord knots using the Mantel-Haenszel technique did not change the significant association between male gender and CS.

CONCLUSION

Male gender is an independent risk factor for adverse pregnancy outcome.

Is abnormal labor associated with shoulder dystocia in nulliparous women?

OBJECTIVE

This study was undertaken to examine the relationship between labor abnormalities and shoulder dystocia in nulliparous women.

STUDY DESIGN

Nulliparous women whose delivery was complicated by shoulder dystocia were studied and compared with a control group selected based on the best possible match for race, labor type (spontaneous or induced), and birth weight. The duration of first and second stage of labor, as well as the rates of labor progress, were calculated and compared between groups.

RESULTS

During this 4-year study period, there were 8010 nulliparous singleton deliveries of which 65 (0.8%) were complicated by shoulder dystocia. Compared with controls, there was no difference in the rate of cervical dilation in the active phase of the first stage of labor. In the shoulder dystocia group, more patients had a second stage of labor greater than 2 hours (22% vs 3%; P <.05) and had operative vaginal deliveries (26% vs 1.5%; P <.001). In shoulder dystocia cases with birth weight greater than 4000 g, 33% had a second stage of labor greater than 2 hours.

CONCLUSION

In our population, the combination of fetal macrosomia, second stage of labor longer than 2 hours and the use of operative vaginal delivery were associated with shoulder dystocia in nulliparous women.

Intrapartum risk factors for permanent brachial plexus injury

OBJECTIVE

The purpose of this study was to compare maternal, neonatal, and second stage of labor characteristics in shoulder dystocia deliveries that result in permanent brachial plexus injury with shoulder dystocia deliveries that result in no injury.

STUDY DESIGN

Our cases were culled from a database of deliveries that resulted in permanent brachial plexus injuries and matched to control cases that were taken from a database of consecutive shoulder dystocia deliveries from one hospital. Deliveries that resulted in injury were excluded from the control cases; those cases with no recorded shoulder dystocia were excluded from the cases. Matching was for birth weight (+/-250 g), parity, and diabetic status. Rates of precipitous and prolonged second stage, operative delivery, neonatal depression, and average number of shoulder dystocia maneuvers used were compared between the two groups with chi(2) test, Fisher exact test, and the Student t test; a probability value of <.05 was considered significant.

RESULTS

There were 80 matched patients, of which 26 patients were nulliparous and 11 patients were diabetic. Mothers of the uninjured group were younger than those of the injured group (23.7+/-6.2 years vs 27.4+/-5.1 years, P<.001). The injured group had a significantly higher rate of 5-minute Apgar scores of <7 (13.9% vs 3.8%, P=.04). Differences in maternal weight, body mass index, height, race, gestational age, average number of maneuvers, head-to-body delivery interval, operative delivery rate, prolonged second stage rate, precipitous second stage rate, and sex were not significant between groups. The rates of precipitous second stage for both groups (28.0% injured and 35.0% uninjured) were more than triple the rates of prolonged second stage (9.5% injured and 11.3% uninjured).

CONCLUSION

No characteristic of second-stage of labor predicts permanent brachial plexus injury. Precipitous second stage is the most prevalent labor abnormality that is associated with shoulder dystocia.

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

OBJECTIVE AND BACKGROUND

To evaluate risk factors for shoulder dystocia and brachial plexus injury using a case-control study at the departments of obstetrics and gynecology at the four largest hospitals in southern Sweden. All cases of shoulder dystocia between 1987 and 1993 inclusive were identified. For each case, two control infants with similar birthweight (+/- 100 g) and identical year of birth were randomly selected.

METHODS

Original maternal records were reviewed and information regarding 10 potential risk factors was extracted. Odds ratios (ORs) were calculated using the Mantel-Haenszel method. Stratification was made for year of delivery, parity (0, I, II, III+), and maternal age (5-year class).

RESULTS

In all, 107 infants with shoulder dystocia and 198 controls were included. The OR was greater than unity for all risk factors except gestational age. Three of the risk factors, induction of labor, epidural analgesia, and instrumental delivery, reached statistical significance. Thirty-four infants also suffered brachial plexus injury, giving a brachial plexus injury rate of 32% among the shoulder dystocia cases. We also made a separate analysis of the nine risk factors for brachial plexus injury following a shoulder dystocia, however none reached statistical significance.

CONCLUSION

In this case-control study based on more than 100,000 deliveries at four large hospitals during a 7-year period, induction of labor, epidural analgesia, and instrumental delivery turned out to be significant risk factors for shoulder dystocia. For brachial plexus injury following shoulder dystocia, no significant risk factor was identified.

Suspected big baby: a difficult clinical problem in obstetrics

BACKGROUND

Large for gestational age fetuses, also called macrosomic fetuses, represent a continuing challenge in obstetrics.

METHODS

We review various problems with large for gestational age fetuses. We have performed a literature search, mainly through the database PubMed (includes the Medline database). The clinical problem is discussed from the primary care provider's, the patient's and the obstetrician's point of view.

RESULTS

Macrosomia is arbitrarily defined as having a fetal weight of above the 90th percentile, a birth weight of above 4000 g or 4500 g, or a birth weight of over +2 standard deviation of the mean birth weight by gestational age. The diagnosis of macrosomia is difficult, both by palpation and symphysis fundus measurement; even with sophisticated sonographic measures. The combination of biparietal diameter, femur length and abdominal circumference appears to be no better than abdominal circumference alone.

INTERPRETATION

Based on the literature, labor should not be induced in nondiabetic pregnancies. The best policy is to await spontaneous birth or to induce labor after 42 weeks completion. A great number of cesarean sections have to be performed to avoid a single case of plexus brachialis paresis resulting from a difficult shoulder delivery. Cesarean section should not be considered in nondiabetic pregnancies unless the estimated fetal weight is above 5000 g. In pregnancies complicated by diabetes mellitus there are reasons for selective induction of labor if macrosomia is suspected and for cesarean section if the calculated birth weight is above 4000 g. Each department should have a strategy to handle such a situation because the problem with the difficult shoulder delivery cannot be completely avoided. Different procedures of managing difficult shoulder delivery are described.

Prepregnancy body mass index in non-diabetic women with and without shoulder dystocia

OBJECTIVE

To investigate the distribution of prepregnancy body mass index (BMI) in non-diabetic women with and without shoulder dystocia.

STUDY DESIGN

Cases were 142 non-diabetic women experiencing shoulder dystocia during the period from 1 January 1993 to 31 December 1999. Shoulder dystocia was defined as the impossibility of delivering the fetal shoulders by standard procedures. Controls were 142 women vaginally delivering during the same period without experiencing shoulder dystocia. Cases and controls were matched for parity (primi-/multipara) and birthweight (+/-250 g). Women with diabetes mellitus, gestational diabetes or a history of shoulder dystocia in a previous birth were excluded. The BMI and selected obstetric data were extracted from an internal database in the department.

RESULTS

Delivery was performed using McRoberts maneuvre (42%), Woods screw (50%) or by primary delivery of the posterior arm (8%). Women experiencing shoulder dystocia had significantly more labor augmentation and more instrumental deliveries. No differences were shown in the prevalence of low Apgarscores. The proportion of children with Erbs palsy and clavicular fracture was very close to be significantly different in cases or controls. However, these data does not allow any conclusion. The distribution of BMI was equal in cases and controls.

CONCLUSION

Non-diabetic women experiencing shoulder dystocia do not have a higher BMI than non-diabetic women delivering without this experience, given a fixed fetal weight.

Shoulder dystocia: an obstetric emergency

Shoulder dystocia is one of the most dreaded complications of vaginal delivery encountered by the obstetrician. Although risk factors for shoulder dystocia exist, approximately 50% of cases do not demonstrate the classic predisposing signs. Obstetricians can help patients decrease their risk for fetal macrosomia by frequent attention to weight gain, nutrition, and exercise during pregnancy and by aggressive management of diabetes. All obstetricians must be familiar with the maneuvers used to effect delivery of impacted shoulders and must be prepared to institute these maneuvers immediately in a crisis situation.

Objective definition of shoulder dystocia: a prospective evaluation

OBJECTIVE

The current study was undertaken to validate the objective definition of shoulder dystocia in a prospectively evaluated group of patients.

STUDY DESIGN

Selected vaginal deliveries from January 1995 to December 1996 (N = 722) were evaluated for head-to-body delivery time and use of ancillary obstetric maneuvers. Charts were reviewed for perinatal and outcome data.

RESULTS

Ninety-nine deliveries were complicated by shoulder dystocia and 623 deliveries had no shoulder dystocia. The objective definition described infants with lower 1-minute Apgar scores and increased birth weight. All fetal injuries were in the shoulder dystocia group. Duration of the second stage was significantly associated with a diagnosis of shoulder dystocia. The risk of shoulder dystocia was increased with maternal diabetes, but it was not correlated with birth weight in diabetics.

CONCLUSIONS

The objective definition of shoulder dystocia identified a group of patients with an increased birth weight and risk of fetal injuries. The use of an objective definition will assist the evaluation of prophylactic and treatment proposals for shoulder dystocia.

Limited usefulness of fetal weight in predicting neonatal brachial plexus injury

OBJECTIVE

The objectives were to determine the neonatal morbidity rate from vaginal birth and examine fetal weight-based injury-prevention strategies.

STUDY DESIGN

Selected neonatal morbidities were categorized by birth weight for all vertex vaginal deliveries occurring during a 12-year period. Sensitivity, specificity, and predictive values for brachial palsy were calculated at increasing birth weight cutoff levels. A policy of cesarean delivery for macrosomic infants was evaluated.

RESULTS

There were 80 cases of brachial palsy among 63,761 infants (0.13%). In mothers without diabetes, rates in the 4500- to 4999-g and >5000-g groups were 3.0% and 6.7%, respectively. A threshold of 3700 g had a sensitivity of 71% and a specificity of 86%; the positive predictive value was 0.56%. To prevent a single case of permanent injury, 155 to 588 cesarean deliveries are required at the currently recommended cutoff weight of 4500 g.

CONCLUSIONS

The rates of lasting morbidity do not justify routine cesarean delivery for infants without diabetic complications weighing <5000 g.