Diagnosis and Management of Macrosomia and Shoulder Dystocia: A Comprehensive Review of Major Guidelines.

Importance: Macrosomia represents the most significant risk factor of shoulder dystocia (SD), which is a severe and emergent complication of vaginal delivery. They are both associated with adverse pregnancy outcomes. Objective: The aim of this study was to review and compare the most recently published influential guidelines on the diagnosis and management of fetal macrosomia and SD. Evidence Acquisition: A comparative review of guidelines from the American College of Obstetricians and Gynecologists (ACOG), the Royal College of Obstetricians and Gynaecologists, the National Institute for Health and Care Excellence, the Royal Australian and New Zealand College of Obstetricians and Gynaecologists (RANZCOG), and the Department for Health and Wellbeing of the Government of South Australia on macrosomia and SD was conducted. Results: The ACOG and RANZCOG agree that macrosomia should be defined as birthweight above 4000-4500 g regardless of the gestational age, whereas the National Institute for Health and Care Excellence defines macrosomia as an estimated fetal weight above the 95th percentile. According to ACOG and RANZCOG, ultrasound scans and clinical estimates can be used to rule out fetal macrosomia, although lacking accuracy. Routine induction of labor before 39 weeks of gestation with the sole indication of suspected fetal macrosomia is unanimously not recommended, but an individualized counseling should be provided. Exercise, appropriate diet, and prepregnancy bariatric surgery are mentioned as preventive measures. There is also consensus among the reviewed guidelines regarding the definition and the diagnosis of SD, with the "turtle sign" being the most common sign for its recognition as well as the poor predictability of the reported risk factors. Moreover, there is an overall agreement on the algorithm of SD management with McRoberts technique suggested as first-line maneuver. In addition, appropriate staff training, thorough documentation, and time keeping are crucial aspects of SD management according to all medical societies. Elective delivery for the prevention of SD is discouraged by all the reviewed guidelines. Conclusions: Macrosomia is associated not only with SD but also with maternal and neonatal complications. Similarly, SD can lead to permanent neurologic sequalae, as well as perinatal death if managed in a suboptimal way. Therefore, it is crucial to develop consistent international practice protocols for their prompt diagnosis and effective management in order to safely guide clinical practice and improve pregnancy outcomes.

Pitfalls in the diagnostics of shoulder dystocia: an analysis based on the scrutiny of 2274 deliveries.

PURPOSE: Shoulder dystocia is an obstetric emergency with severe complications. Our objective was to evaluate the major pitfalls in the diagnostics of shoulder dystocia, diagnostic descriptions documented in medical records, use of obstetric maneuvers, and their correlations to Erb's and Klumpke's palsy and the use of ICD-10 code 066.0. METHODS: A retrospective, register-based case-control study included all deliveries (n = 181 352) in Hospital District of Helsinki and Uusimaa (HUS) area in 2006-2015. Potential shoulder dystocia cases (n = 1708) were identified from the Finnish Medical Birth Register and the Hospital Discharge Register using ICD-10 codes O66.0, P13.4, P14.0, and P14.1. After thorough assessment of all medical records, 537 shoulder dystocia cases were confirmed. Control group consisted of 566 women without any of these ICD-10 codes. RESULTS: The pitfalls in the diagnostic included suboptimal following of guidelines for making the diagnosis of shoulder dystocia, subjective interpretation of diagnostic criteria, and inexact or inadequate documentation in medical records. The diagnostic descriptions in medical record were highly inconsistent. The use of obstetric maneuvers was suboptimal among shoulder dystocia cases (57.5%). Overall, the use of obstetric maneuvers increased during the study period (from 25.7 to 97.0%, p < 0.001), which was associated with decreasing rate of Erb's palsy and increasing use of ICD-10 code O66.0. CONCLUSION: There are diagnostic pitfalls, which could be addressed by education regarding shoulder dystocia guidelines, by improved use obstetric maneuvers, and more precise documentation. The increased use of obstetric maneuvers was associated with lower rates of Erb's palsy and improved coding of shoulder dystocia.

A new approach to predicting shoulder dystocia: fetal clavicle measurement

Background/aim: This study aimed to evaluate the relationship between second- and third-trimester clavicle lengths and birth weight and shoulder dystocia. Materials and methods: This prospective observational study included 181 patients who presented to the Private Etlik Lokman Hekim Hospital for routine pregnancy visits between March 2019 and March 2020. In addition to routine pregnancy examinations, the patients also underwent ultrasonography twice at weeks 20­23 and 33­36 to determine the length of the fetal clavicle. The patients were evaluated for shoulder dystocia in the second stage of labor. The birth weight of the neonates was recorded. The primary objective of this study was to establish the relationship between third-trimester clavicle length and shoulder dystocia. Results: Fetal clavicle length increases in the second trimester with the advancing gestational week but does not significantly change in the third trimester. We did not observe any significant difference for second trimester clavicle length between the type of delivery, birth weight, or shoulder dystocia. Moreover, we did not observe any significant difference for third trimester clavicle length between types of delivery. However, we found a significant relationship between third trimester clavicle length and birth weight and shoulder dystocia. The median third-trimester clavicle length was 39.5 mm (range: 30.7­43.9) in neonates who did not develop shoulder dystocia and 42.5 mm (range: 41.4­43.1) in the 3 neonates who developed shoulder dystocia. The third-trimester clavicle length cut-off for shoulder dystocia was calculated as 41.35 mm (sensitivity: 100.00%, specificity: 83.82%, accuracy: 84.5%). The third-trimester clavicle length cut-off for macrosomia (defined as birth weight of ≥4100 g) was 40.75 mm (sensitivity: 87.50%, specificity: 77.56%, accuracy: 78.05%). Conclusion: Third-trimester fetal clavicle length, an important component of biacromial diameter, as measured by ultrasonography, is a practical and significant method for predicting macrosomia and shoulder dystocia.

Circumferential shoulder laceration after posterior axilla sling traction: a case report of severe shoulder dystocia.

BACKGROUND: Shoulder dystocia is an unpredictable and potentially catastrophic complication of vertex vaginal delivery. Posterior axilla sling traction (PAST) has recently been proposed as a method to resolve severe shoulder dystocia when commonly used techniques have failed. CASE PRESENTATION: A 33-year-old woman (gravida 5, para 0) at 35 weeks, 1 day gestation underwent induction of labor for poorly controlled type 2 diabetes mellitus. Delivery of the large-for-gestational-age infant (4,060 g) was complicated by intractable shoulder dystocia, relieved at 3 minutes with PAST, resulting in a deep, circumferential laceration of the fetal posterior shoulder and contralateral phrenic nerve palsy. CONCLUSIONS: PAST provides a potentially lifesaving option during intractable shoulder dystocia. Simulation or education about the technique facilitates its use when standard maneuvers fail. It is important to disseminate information about potential complications associated with these novel maneuvers.

Shoulder Dystocia: Managing an Obstetric Emergency.

Shoulder dystocia is an obstetric emergency in which normal traction on the fetal head does not lead to delivery of the shoulders. This can cause neonatal brachial plexus injuries, hypoxia, and maternal trauma, including damage to the bladder, anal sphincter, and rectum, and postpartum hemorrhage. Although fetal macrosomia, prior shoulder dystocia, and preexisting or gestational diabetes mellitus increases the risk of shoulder dystocia, most cases occur without warning. Labor and delivery teams should always be prepared to recognize and treat this emergency. Training and simulation exercises improve physician and team performance when shoulder dystocia occurs. Unequivocally announcing that dystocia is happening, summoning extra assistance, keeping track of the time from delivery of the head to full delivery of the neonate, and communicating with the patient and health care team are helpful. Calm and thoughtful use of release maneuvers such as knee to chest (McRoberts maneuver), suprapubic pressure, posterior arm or shoulder delivery, and internal rotational maneuvers will almost always result in successful delivery. When these are unsuccessful, additional maneuvers, including intentional clavicular fracture or cephalic replacement, may lead to delivery. Each institution should consider the length of time it will take to prepare the operating room for general inhalational anesthesia and abdominal rescue and practice this during simulation exercises.

Development and validation of a machine-learning model for prediction of shoulder dystocia.

OBJECTIVES: To develop a machine-learning (ML) model for prediction of shoulder dystocia (ShD) and to externally validate the model's predictive accuracy and potential clinical efficacy in optimizing the use of Cesarean delivery in the context of suspected macrosomia. METHODS: We used electronic health records (EHR) from the Sheba Medical Center in Israel to develop the model (derivation cohort) and EHR from the University of California San Francisco Medical Center to validate the model's accuracy and clinical efficacy (validation cohort). Subsequent to application of inclusion and exclusion criteria, the derivation cohort included 686 singleton vaginal deliveries, of which 131 were complicated by ShD, and the validation cohort included 2584 deliveries, of which 31 were complicated by ShD. For each of these deliveries, we collected maternal and neonatal delivery outcomes coupled with maternal demographics, obstetric clinical data and sonographic fetal biometry. Biometric measurements and their derived estimated fetal weight were adjusted (aEFW) according to gestational age at delivery. A ML pipeline was utilized to develop the model. RESULTS: In the derivation cohort, the ML model provided significantly better prediction than did the current clinical paradigm based on fetal weight and maternal diabetes: using nested cross-validation, the area under the receiver-operating-characteristics curve (AUC) of the model was 0.793 ± 0.041, outperforming aEFW combined with diabetes (AUC = 0.745 ± 0.044, P = 1e-16 ). The following risk modifiers had a positive beta that was > 0.02, i.e. they increased the risk of ShD: aEFW (beta = 0.164), pregestational diabetes (beta = 0.047), prior ShD (beta = 0.04), female fetal sex (beta = 0.04) and adjusted abdominal circumference (beta = 0.03). The following risk modifiers had a negative beta that was < -0.02, i.e. they were protective of ShD: adjusted biparietal diameter (beta = -0.08) and maternal height (beta = -0.03). In the validation cohort, the model outperformed aEFW combined with diabetes (AUC = 0.866 vs 0.784, P = 0.00007). Additionally, in the validation cohort, among the subgroup of 273 women carrying a fetus with aEFW ≥ 4000 g, the aEFW had no predictive power (AUC = 0.548), and the model performed significantly better (0.775, P = 0.0002). A risk-score threshold of 0.5 stratified 42.9% of deliveries to the high-risk group, which included 90.9% of ShD cases and all cases accompanied by maternal or newborn complications. A more specific threshold of 0.7 stratified only 27.5% of the deliveries to the high-risk group, which included 63.6% of ShD cases and all those accompanied by newborn complications. CONCLUSION: We developed a ML model for prediction of ShD and, in a different cohort, externally validated its performance. The model predicted ShD better than did estimated fetal weight either alone or combined with maternal diabetes, and was able to stratify the risk of ShD and neonatal injury in the context of suspected macrosomia. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

A retrospective analysis of risk factors for clavicle fractures in newborns with shoulder dystocia and brachial plexus injury: A single-center experience.

OBJECTIVE: We aimed to analyze the risk factors for clavicle fractures in newborns with shoulder dystocia and brachial plexus injury and to determine whether their incidence is associated with local characteristics. METHODS: This study was conducted as a retrospective trial between January 2017 and December 2018. Patients with clavicular fracture who were hospitalized in the neonatal intensive care unit of a community hospital were retrospectively analyzed. The clavicular fracture cohort was first divided into two groups and then two subgroups: patients with/without shoulder dystocia and patients with/without a brachial plexus injury. Peripartum and neonatal risk factors of these patients were reviewed using the patient information system. Any additional neurological or musculoskeletal trauma was noted. A multivariate logistic regression analysis was performed to determine independent predictors of shoulder dystocia and brachial plexus injury. RESULTS: A total of 46 patients with shoulder dystocia in 25 (54%) and brachial plexus injury in 12 (26%) were included in the study. The birth weight of patients with shoulder dystocia was 4,164.2±412.7 g, and that of patients without was 3,535.8±865.2 g (p=0.003). In 11 of 14 patients (44%) in whom labor was induced and whose infant had a fractured clavicle, the infant also had shoulder dystocia (p=0.029). Brachial plexus injury was found in 8 (66.7%) of 14 infants who were born by induced labor and who had a clavicular fracture (p=0.002). The regression analysis revealed that age and induction of labor were independent risk factors for brachial plexus injury (odds ratio=1.599 and 81.862, respectively). Gestational weight gain (p=0.003) and neonatal birth weight (p=0.047) were also found as independent risk factors for shoulder dystocia. CONCLUSION: Evidence from this study has shown that not only birth age or birth weight but also excessive weight gain by mother and induction of labor may increase the risk of clavicula fracture with brachial plexus palsy. Advanced maternal age, multiparity, and deliveries after 39 weeks seem to be risk factors for a clavicular fracture with a brachial plexus injury. LEVEL OF EVIDENCE: Level IV, Therapeutic study.

Risk factors associated with neonatal brachial plexus palsy in the United States.

Neonatal brachial plexus palsy (NBPP) is a birth injury that can cause severe functional loss in the affected limb. The purpose of this study was to determine the temporal changes in the national incidence of this condition and whether associated risk factors have changed over time. Children born via vaginal delivery were identified in the Kids' Inpatient Database (KID) from 1997 to 2012, and those with NBPP were identified. The trend in incidence and risk factors were assessed through the study period. The nationwide incidence of NBPP decreased during the study period. Infants with shoulder dystocia, fetal macrosomia, and gestational diabetes had the highest risk of developing NBPP, while multiple birth mates during delivery had a protective effect. Multiple risk factors, including shoulder dystocia, macrosomia, and heavy for dates became less predictive of the development of NBPP over time. Several risk factors predispose children to the development of NBPP, and the effect of these risk factors has been changing. This information can guide obstetric treatment to help prevent NBPP. Level of evidence is diagnostic, level 3.

Risk of recurrent shoulder dystocia: are we any closer to prediction?

Objective: To determine the incidence and risk factors for recurrent shoulder dystocia in women. Methods: We searched Medline, Pubmed, Embase, and CINAHL for relevant articles in English and French from 1980 to February 2018 that described risks of recurrent shoulder dystocia undergoing a trial of labour in subsequent pregnancies. A total of 684 articles were found, of which 13 were included as they met criteria. We extracted data on study characteristics, incidence of recurrent shoulder dystocia, degree of neonatal injury, and presence of known risk factors. Results: There was a wide variation in the incidence of shoulder dystocia in subsequent pregnancies from 1-25%. The largest cohort reported a risk of 13.5%. The most important risk factor for recurrent shoulder dystocia is an increase in birthweight in the subsequent pregnancy compared to the index pregnancy (OR 7-12). Prolonged second stage, instrumental delivery, maternal diabetes, increased maternal BMI, and severe neonatal morbidity in the index pregnancy were also associated with an increased risk of recurrent shoulder dystocia. However, many of these risk factors were present in women who did not have a recurrent shoulder dystocia. In addition, women with recurrent shoulder dystocia rarely had identifiable risk factors, other than the history of previous shoulder dystocia. Sample sizes were low as most studies are single centre, retrospective cohorts with low rates of subsequent pregnancy and vaginal birth as many women may have elected to have a caesarean section in subsequent pregnancies or were lost to follow up. There was a high rate of reporting bias and heterogeneity, prohibiting formal meta-analyses. Conclusion: Recurrent shoulder dystocia is an unpredictable obstetric complication with potentially devastating consequences. Individual assessment and thorough counselling should be offered to women contemplating a subsequent planned vaginal birth with specific attention paid to those women where the estimated birthweight is >4000 g or greater than in the index pregnancy.