Human shoulder development is adapted to obstetrical constraints.

In humans, obstetrical difficulties arise from the large head and broad shoulders of the neonate relative to the maternal birth canal. Various characteristics of human cranial development, such as the relatively small head of neonates compared with adults and the delayed fusion of the metopic suture, have been suggested to reflect developmental adaptations to obstetrical constraints. On the other hand, it remains unknown whether the shoulders of humans also exhibit developmental features reflecting obstetrical adaptation. Here we address this question by tracking the development of shoulder width from fetal to adult stages in humans, chimpanzees, and Japanese macaques. Compared with nonhuman primates, shoulder development in humans follows a different trajectory, exhibiting reduced growth relative to trunk length before birth and enhanced growth after birth. This indicates that the perinatal developmental characteristics of the shoulders likely evolved to ease obstetrical difficulties such as shoulder dystocia in humans.

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.

Prescriptive and proscriptive lessons for managing shoulder dystocia: a technical and videographical tutorial.

This tutorial of the intrapartum management of shoulder dystocia uses drawings and videos of simulated and actual deliveries to illustrate the biomechanical principles of specialized delivery maneuvers and examine missteps associated with brachial plexus injury. It is intended to complement haptic, mannequin-based simulation training. Demonstrative explication of each maneuver is accompanied by specific examples of what not to do. Positive (prescriptive) instruction prioritizes early use of direct fetal manipulation and stresses the importance of determining the alignment of the fetal shoulders by direct palpation, and that the biacromial width should be manually adjusted to an oblique orientation within the pelvis-before application of traction to the fetal head, the biacromial width is manually adjusted to an oblique orientation within the pelvis. Negative (proscriptive) instructions includes the following: to avoid more than usual and/or laterally directed traction, to use episiotomy only as a means to gain access to the posterior shoulder and arm, and to use a 2-step procedure in which a 60-second hands-off period ("do not do anything") is inserted between the emergence of the head and any initial attempts at downward traction to allow for spontaneous rotation of the fetal shoulders. The tutorial presents a stepwise approach focused on the delivering clinician's tasks while including the role of assistive techniques, including McRoberts, Gaskin, and Sims positioning, suprapubic pressure, and episiotomy. Video footage of actual deliveries involving shoulder dystocia and permanent brachial plexus injury demonstrates ambiguities in making the diagnosis of shoulder dystocia, risks of improper traction and torsion of the head, and overreliance on repeating maneuvers that prove initially unsuccessful.

Perinatal outcome of fetuses predicted to be large-for-gestational age on universal third-trimester ultrasound in non-diabetic pregnancy.

OBJECTIVE: To describe the perinatal outcome of fetuses predicted to be large-for-gestational age (LGA) on universal third-trimester ultrasound in non-diabetic pregnancies of women attempting vaginal delivery. METHODS: This was a prospective population-based cohort study of patients from a single tertiary maternity unit in the UK offering universal third-trimester ultrasound and practicing expectant management of suspected LGA until 41-42 weeks. All women with a singleton pregnancy and an estimated due date between January 2014 and September 2019 were included. Women delivering before 37 weeks, those having a planned Cesarean delivery, those with pre-existing or gestational diabetes, those with fetal abnormalities and those who did not undergo a third-trimester scan were excluded from the assessment of perinatal outcome of cases with LGA predicted on ultrasound after implementation of the universal scan period. Association of LGA on universal third-trimester ultrasound screening and perinatal adverse outcome was assessed, with the exposures of interest being estimated fetal weight (EFW) at the 90th -95th , > 95th and > 99th percentile. The reference group was composed of fetuses with EFW at the 30th -70th percentile. Analysis was performed using multivariate logistic regression. The evaluated adverse perinatal outcomes included a composite outcome of admission to neonatal intensive care unit, Apgar score < 7 at 5 min and arterial cord pH < 7.1 (CAO1) and a composite outcome of stillbirth, neonatal death and hypoxic ischemic encephalopathy (CAO2). Secondary maternal outcomes were induction of labor, mode of delivery, postpartum hemorrhage, shoulder dystocia and obstetric anal sphincter injury. RESULTS: Cases with EFW > 95th percentile on universal third-trimester scan were at increased risk of CAO1 (adjusted odds ratio (aOR), 2.18 (95% CI, 1.69-2.80)) and CAO2 (aOR, 2.58 (95% CI, 1.05-6.34)). Cases with EFW at the 90th -95th percentile had a less pronounced increase in the risk of CAO1 (aOR, 1.35 (95% CI, 1.02-1.78)) and were not at increased risk of CAO2. All pregnancies with a fetus predicted to be LGA were at increased risk of all of the evaluated secondary maternal outcomes except for obstetric anal sphincter injury. The risk of adverse maternal outcome was typically higher with increasing EFW. Post-hoc exploration of data suggested that shoulder dystocia had a limited contribution to composite adverse perinatal outcomes in LGA cases (population attributable fraction of 10.8% for CAO1 and 29.1% for CAO2). CONCLUSIONS: Cases with EFW > 95th percentile are at increased risk of severe adverse perinatal outcome, such as death and hypoxic ischemic encephalopathy. These findings should aid antenatal counseling regarding the associated risk and delivery options. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Timing of induction of labor in suspected macrosomia: retrospective cohort study, systematic review and meta-analysis.

OBJECTIVES: Large-for-gestational age (LGA) is associated with several adverse maternal and neonatal outcomes. Although many studies have found that early induction of labor (IOL) in case of a LGA fetus reduces the incidence of shoulder dystocia, no current guidelines recommend this particular clinical strategy, owing to concerns about increased rates of Cesarean delivery (CD) and neonatal complications. The purpose of this study was to assess whether the timing of IOL in LGA fetuses affected maternal and neonatal outcomes in a single center, and to combine these results with evidence reported in the literature. METHODS: This study comprised two parts. The first part was a retrospective cohort study that included consecutive patients with a singleton pregnancy and an estimated fetal weight ≥ 90th percentile on ultrasound between 35 + 0 and 39 + 0 weeks' gestation, who were eligible for normal vaginal delivery. The second part of the study was a systematic review of the literature and meta-analysis, including the results of our cohort study as well as those of previous studies that compared IOL with expectant management in patients with a LGA fetus. The perinatal outcomes of the study were CD, operative vaginal delivery, shoulder dystocia, brachial plexus palsy, anal sphincter injury, postpartum hemorrhage, Apgar score, umbilical artery pH, admission to the neonatal intensive care unit, use of continuous positive airway pressure, intracranial hemorrhage, need for phototherapy and bone fracture. RESULTS: Of the 547 patients included in this retrospective cohort study, 329 (60.1%) underwent IOL and 218 (39.9%) experienced spontaneous labor. Following covariate balancing, the odds of CD were significantly higher in the IOL group compared with the spontaneous-labor group. This difference only became apparent beyond 40 weeks' gestation (hazard ratio, 1.90; P = 0.030). The difference between the IOL and spontaneous-labor groups for the rate of shoulder dystocia was not statistically significant (hazard ratio, 1.57; P = 0.200). Seventeen studies, in addition to our own results, were included in the systematic review and meta-analysis, giving a total population of 111 300 participants. Although there was no significant difference in the rate of CD between IOL and expectant management after pooling the results of included studies, the risk for shoulder dystocia was significantly lower in the IOL group (odds ratio (OR), 0.64 (95% CI, 0.42-0.98); I2 = 19% from 12 studies) when considering only IOL performed before 40 + 0 weeks. When the studies in which IOL was carried out exclusively before 40 + 0 weeks were removed from the analysis, the risk for CD in the remaining studies was significantly higher in the IOL group (OR, 1.46 (95% CI, 1.02-2.09); I2 = 56%). There were no statistically significant differences between the IOL and expectant-management groups for the remaining perinatal outcomes. Nulliparity, history of CD and low Bishop score, but not method of induction, were independent risk factors for intrapartum CD in patients that underwent IOL for LGA. CONCLUSIONS: The timing of IOL in patients with suspected macrosomia significantly impacts on perinatal adverse outcomes. IOL has no impact on rates of shoulder dystocia but increases the odds of CD when considered irrespective of gestational age; in contrast, IOL may decrease the risk of shoulder dystocia without increasing the risk of other adverse maternal outcomes, in particular CD, when performed before 40 + 0 weeks (GRADE: low/very low). © 2024 International Society of Ultrasound in Obstetrics and Gynecology.

Video analysis of real-life shoulder dystocia to assess technical and non-technical performance.

INTRODUCTION: Managing obstetric shoulder dystocia requires swift action using correct maneuvers. However, knowledge of obstetric teams' performance during management of real-life shoulder dystocia is limited, and the impact of non-technical skills has not been adequately evaluated. We aimed to analyze videos of teams managing real-life shoulder dystocia to identify clinical challenges associated with correct management and particular non-technical skills correlated with high technical performance. MATERIAL AND METHODS: We included 17 videos depicting teams managing shoulder dystocia in two Danish delivery wards, where deliveries were initially handled by midwives, and consultants were available for complications. Delivery rooms contained two or three cameras activated by Bluetooth upon obstetrician entry. Videos were captured 5 min before and after activation. Two obstetricians assessed the videos; technical performances were scored as low (0-59), average (60-84), or high (85-100). Two other assessors evaluated non-technical skills using the Global Assessment of Team Performance checklist, scoring 6 (poor) to 30 (excellent). We used a spline regression model to explore associations between these two score sets. Inter-rater agreement was assessed using interclass correlation coefficients. RESULTS: Interclass correlation coefficients were 0.71 (95% confidence interval 0.23-0.89) and 0.82 (95% confidence interval 0.52-0.94) for clinical and non-technical performances, respectively. Two teams had low technical performance scores; four teams achieved high scores. Teams adhered well to guidelines, demonstrating limited head traction, McRoberts maneuver, and internal rotation maneuvers. Several clinical skills posed challenges, notably recognizing shoulder impaction, applying suprapubic pressure, and discouraging women from pushing. Two non-technical skills were associated with high technical performance: effective patient communication, with teams calming the mother and guiding her collaboration during internal rotational maneuvers, and situation awareness, where teams promptly mobilized all essential personnel (senior midwife, consultant, pediatric team). Team communication, stress management, and task management skills were not associated with high technical performance. CONCLUSIONS: Videos capturing teams managing real-life shoulder dystocia are an effective tool to reveal challenges with certain technical and non-technical skills. Teams with high technical performance are associated with effective patient communication and situational awareness. Future training should include technical skills and non-technical skills, patient communication, and situation awareness.

Shoulder dystocia by severity in families: A nationwide population study.

INTRODUCTION: Previous studies have established a history of shoulder dystocia as an important risk factor for shoulder dystocia, but studies on shoulder dystocia by severity are scarce. It is unknown if shoulder dystocia tends to be passed on between generations. We aimed to assess the recurrence risk of shoulder dystocia by severity in the same woman and between generations on both the maternal and paternal side. We also assessed the likelihood of a second delivery and planned cesarean section after shoulder dystocia. MATERIAL AND METHODS: This was a population-based cohort study, using data from the Medical Birth Registry of Norway. To study recurrence in the same mother, we identified 1 091 067 pairs of first and second, second and third, and third and fourth births in the same mother. To study intergenerational recurrence, we identified an individual both as a newborn and as a mother or father in 824 323 mother-offspring pairs and 614 663 father-offspring pairs. We used Bayesian log-binomial multilevel regression to calculate relative risks (RR) with 95% credible intervals. RESULTS: In subsequent deliveries in the same woman the unadjusted RR of recurrence was 7.05 (95% credible interval 6.39-7.79) and 2.99 (2.71-3.31) after adjusting for possible confounders, including current birthweight. The RRs were higher with severe shoulder dystocia as exposure or outcome. With severe shoulder dystocia as both exposure and outcome, unadjusted and adjusted RR was 20.42 (14.25-29.26) and 6.29 (4.41-8.99), respectively. Women with severe and mild shoulder dystocia and those without had subsequent delivery rates of 71.1, 68.9 and 69.0%, respectively. However, the rates of planned cesarean section in subsequent deliveries for those without shoulder dystocia, mild and severe were 1.3, 5.2 and 16.0%, respectively. On the maternal side the unadjusted inter-generational RR of recurrence was 2.82 (2.25-3.54) and 1.41 (1.05-1.90) on the paternal side. Corresponding adjusted RRs were 1.90 (1.51-2.40) and 1.19 (0.88-1.61), respectively. CONCLUSIONS: We found a strong recurrence risk of shoulder dystocia, especially severe, in subsequent deliveries in the same woman. The inter-generational recurrence risk was higher on the maternal than paternal side. Women with a history of shoulder dystocia had more often planned cesarean section.

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.

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

INTRODUCTION: Shoulder dystocia is a rare obstetric complication, and the risk of recurrence is important for planning future deliveries. MATERIAL AND METHODS: The objectives of our study were to estimate the incidence and risk factors for recurrence of shoulder dystocia and to identify women at high risk of recurrence in a subsequent vaginal delivery. The study design was a nationwide register-based study including data from the Danish Medical Birth Registry and National Patient Register in the period 2007-2017. Nulliparous women with a singleton fetus in cephalic presentation were included for analysis of risk factors in index and subsequent delivery. RESULTS: During the study period, 6002 cases of shoulder dystocia were reported with an overall incidence among women with vaginal delivery of 1.2%. Among 222 225 nulliparous women with vaginal births, shoulder dystocia complicated 2209 (1.0%) deliveries. A subsequent birth was registered in 1106 (50.1%) of the women with shoulder dystocia in index delivery of which 837 (77.8%) delivered vaginally. Recurrence of shoulder dystocia was reported in 60 (7.2%) with a six-fold increased risk compared with women without a prior history of shoulder dystocia (risk ratio [RR] 5.70, 95% confidence interval [CI]: 4.41 to 7.38; adjusted RR 3.06, 95% CI: 2.03 to 4.68). Low maternal height was a significant risk factor for recurrence of shoulder dystocia. In the subsequent delivery, significant risk factors for recurrence were birthweight >4000 g, positive fetal weight difference exceeding 250 g from index to subsequent delivery, stimulation with oxytocin and operative vaginal delivery. In the subsequent pregnancy following shoulder dystocia, women who underwent a planned cesarean (n = 176) were characterized by more advanced age and a higher prevalence of diabetes in the subsequent pregnancy. Furthermore, they had more often experienced operative vaginal delivery, severe perineal lacerations, and severe neonatal complications at the index delivery. CONCLUSIONS: The incidence of shoulder dystocia among nulliparous women with vaginal delivery was 1.0% with a 7.2% risk of recurrence in a population where about 50% had a subsequent birth and of these 78% had subsequent vaginal delivery. Important risk factors for recurrence were low maternal height, increase of birthweight ≥250 g from index to subsequent delivery and operative vaginal delivery.

Shoulder dystocia in babies born to Aboriginal mothers with diabetes: a population-based cohort study, 1998-2015.

BACKGROUND: Australian Aboriginal and Torres Strait Islander women with diabetes in pregnancy (DIP) are more likely to have glycaemic levels above the target range, and their babies are thus at higher risk of excessive fetal growth. Shoulder dystocia, defined by failure of spontaneous birth of fetal shoulder after birth of the head requiring obstetric maneuvers, is an obstetric emergency that is strongly associated with DIP and fetal size. The aim of this study was to investigate the epidemiology of shoulder dystocia in Aboriginal babies born to mothers with DIP. METHODS: Stratifying by Aboriginal status, characteristics of births complicated by shoulder dystocia in women with and without DIP were compared and incidence and time-trends of shoulder dystocia were described. Compliance with guidelines aiming at preventing shoulder dystocia in women with DIP were compared. Post-logistic regression estimation was used to calculate the population attributable fractions (PAFs) for shoulder dystocia associated with DIP and to estimate probabilities of shoulder dystocia in babies born to mothers with DIP at birthweights > 3 kg. RESULTS: Rates of shoulder dystocia from vaginal births in Aboriginal babies born to mothers with DIP were double that of their non-Aboriginal counterparts (6.3% vs 3.2%, p < 0.001), with no improvement over time. Aboriginal mothers with diabetes whose pregnancies were complicated by shoulder dystocia were more likely to have a history of shoulder dystocia (13.1% vs 6.3%, p = 0.032). Rates of guideline-recommended elective caesarean section in pregnancies with diabetes and birthweight > 4.5 kg were lower in the Aboriginal women (28.6% vs 43.1%, p = 0.004). PAFs indicated that 13.4% (95% CI: 9.7%-16.9%) of shoulder dystocia cases in Aboriginal (2.7% (95% CI: 2.1%-3.4%) in non-Aboriginal) women were attributable to DIP. Probability of shoulder dystocia among babies born to Aboriginal mothers with DIP was higher at birthweights > 3 kg. CONCLUSIONS: Aboriginal mothers with DIP had a higher risk of shoulder dystocia and a stronger association between birthweight and shoulder dystocia. Many cases were recurrent. These factors should be considered in clinical practice and when counselling women.

Studying the Effects of Shoulder Dystocia and Neonate-Focused Delivery Maneuvers on Brachial Plexus Strain: A Computational Study.

The purpose of this computational study was to investigate the effects of neonate-focused clinical delivery maneuvers on brachial plexus (BP) during shoulder dystocia. During shoulder dystocia, the anterior shoulder of the neonate is obstructed behind the symphysis pubis of the maternal pelvis, postdelivery of the neonate's head. This is managed by a series of clinical delivery maneuvers. The goal of this study was to simulate these delivery maneuvers and study their effects on neonatal BP strain. Using madymo models of a maternal pelvis and a 90th-percentile neonate, various delivery maneuvers and positions were simulated including the lithotomy position alone of the maternal pelvis, delivery with the application of various suprapubic pressures (SPPs), neonate in an oblique position, and during posterior arm delivery maneuver. The resulting BP strain (%) along with the required maternal delivery force was reported in these independently simulated scenarios. The lithotomy position alone served as the baseline. Each of the successive maneuvers reported a decrease in the required delivery force and resulting neonatal BP strain. As the applied SPP force increased (three scenarios simulated), the required maternal delivery force and neonatal BP strain decreased. A further decrease in both delivery force and neonatal BP strain was observed in the oblique position, with the lowest delivery force and neonatal BP strain reported during the posterior arm delivery maneuver. Data obtained from the improved computational models in this study enhance our understanding of the effects of clinical maneuvers on neonatal BP strain during complicated birthing scenarios such as shoulder dystocia.

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.

Predictors of maternal and neonatal outcomes in labors complicated by shoulder dystocia: a comparative analysis.

INTRODUCTION: Studies investigating the risk factors associated with unfavorable maternal/neonatal outcomes in cases of shoulder dystocia are scarce. This study aims to uncover the predictive factors that give rise to unfavorable outcomes within the context of shoulder dystocia. MATERIALS AND METHODS: Medical records of pregnancies complicated by shoulder dystocia was obtained between 2008-2022 from a single tertiary center. This study involved the comparison of sociodemographic, sonographic, and delivery characteristics among pregnancies complicated by shoulder dystocia resulting in favorable vs. unfavorable maternal/neonatal outcomes. RESULTS: A total of 275 pregnancies were analyzed, with 111 (40.3%) classified as unfavorable outcomes and 164 (59.7%) as favorable outcomes. Employing a multivariable regression analysis, several independent associations were identified with unfavorable maternal/neonatal outcomes. Specifically, short maternal stature, pre-gestational diabetes, vacuum extraction, Wood's screw maneuver, and macrosomia merged as significant predictors of unfavorable maternal/neonatal outcomes. CONCLUSION: Short maternal stature, pre-gestational diabetes, vacuum extraction, Wood's screw maneuver, and macrosomia may all contribute to poor maternal/neonatal outcomes in shoulder dystocia cases. This knowledge allows clinicians to improve their decision-making, patient care, and counseling.

Forensic Identification and Evaluation of 25 Obstetric Brachial Plexus Palsy Medical Damage Cases.

OBJECTIVES: To analyze the high risk factors of obstetric brachial plexus palsy (OBPP), and to explore how to evaluate the relationship between fault medical behavior and OBPP in the process of medical damage forensic identification. METHODS: A retrospective analysis was carried out on 25 cases of medical damage liability disputes related to OBPP from 2017 to 2021 in Beijing Fayuan Judicial Science Evidence Appraisal Center. The shortcomings of hospitals in birth weight assessment, delivery mode selection, labor process observation and shoulder dystocia management, and the causal relationship between them and the damage consequences of the children were summarized. RESULTS: Fault medical behavior was assessed as the primary cause in 2 cases, equal cause in 10 cases, secondary cause in 8 cases, minor cause in 1 case, no causal relationship in 1 case, and unclear causal force in 3 cases. CONCLUSIONS: In the process of forensic identification of OBPP, whether medical behaviors fulfill diagnosis and treatment obligations should be objectively analyzed from the aspects of prenatal evaluation, delivery mode notification, standardized use of oxytocin, standard operation of shoulder dystocia, etc. Meanwhile, it is necessary to fully consider the objective risk of different risk factors and the difficulty of injury prevention, and comprehensively evaluate the causal force of fault medical behavior in the damage consequences.

Impact of simulation training on the management of shoulder dystocia and incidence of permanent brachial plexus birth injury: An observational study.

OBJECTIVE: To study the impact of shoulder dystocia (SD) simulation training on the management of SD and the incidence of permanent brachial plexus birth injury (BPBI). DESIGN: Retrospective observational study. SETTING: Helsinki University Women's Hospital, Finland. SAMPLE: Deliveries with SD. METHODS: Multi-professional, regular and systematic simulation training for obstetric emergencies began in 2015, and SD was one of the main themes. A study was conducted to assess changes in SD management and the incidence of permanent BPBI. The study period was from 2010 to 2019; years 2010-2014 were considered the pre-training period and years 2015-2019 were considered the post-training period. MAIN OUTCOME MEASURES: The primary outcome measure was the incidence of permanent BPBI after the implementation of systematic simulation training. Changes in the management of SD were also analysed. RESULTS: During the study period, 113 085 vertex deliveries were recorded. The incidence of major SD risk factors (gestational diabetes, induction of labour, vacuum extraction) increased and was significantly higher for each of these factors during the post-training period (p < 0.001). The incidence of SD also increased significantly (0.01% vs 0.3%, p < 0.001) during the study period, but the number of children with permanent BPBI decreased by 55% after the implementation of systematic simulation training (0.05% vs 0.02%, p < 0.001). The most significant change in the management of SD was the increased incidence of successful delivery of the posterior arm. CONCLUSIONS: Systematic simulation-based training of midwives and doctors can translate into improved individual and team performance and can significantly reduce the incidence of permanent BPBI.

Induction of labour at or near term for suspected fetal macrosomia.

BACKGROUND: Women with a suspected large-for-dates fetus or a fetus with suspected macrosomia (birthweight greater than 4000 g) are at risk of operative birth or caesarean section. The baby is also at increased risk of shoulder dystocia and trauma, in particular fractures and brachial plexus injury. Induction of labour may reduce these risks by decreasing the birthweight, but may also lead to longer labours and an increased risk of caesarean section. OBJECTIVES: To assess the effects of a policy of labour induction at or shortly before term (37 to 40 weeks) for suspected fetal macrosomia on the way of giving birth and maternal or perinatal morbidity. SEARCH METHODS: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 January 2016), contacted trial authors and searched reference lists of retrieved studies. SELECTION CRITERIA: Randomised trials of induction of labour for suspected fetal macrosomia. DATA COLLECTION AND ANALYSIS: Review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy. We contacted study authors for additional information. For key outcomes the quality of the evidence was assessed using the GRADE approach. MAIN RESULTS: We included four trials, involving 1190 women. It was not possible to blind women and staff to the intervention, but for other 'Risk of bias' domains these studies were assessed as being at low or unclear risk of bias. Compared to expectant management, there was no clear effect of induction of labour for suspected macrosomia on the risk of caesarean section (risk ratio (RR) 0.91, 95% confidence interval (CI) 0.76 to 1.09; 1190 women; four trials, moderate-quality evidence) or instrumental delivery (RR 0.86, 95% CI 0.65 to 1.13; 1190 women; four trials, low-quality evidence). Shoulder dystocia (RR 0.60, 95% CI 0.37 to 0.98; 1190 women; four trials, moderate-quality evidence), and fracture (any) (RR 0.20, 95% CI 0.05 to 0.79; 1190 women; four studies, high-quality evidence) were reduced in the induction of labour group. There were no clear differences between groups for brachial plexus injury (two events were reported in the control group in one trial, low-quality evidence). There was no strong evidence of any difference between groups for measures of neonatal asphyxia; low five-minute infant Apgar scores (less than seven) or low arterial cord blood pH (RR 1.51, 95% CI 0.25 to 9.02; 858 infants; two trials, low-quality evidence; and, RR 1.01, 95% CI 0.46 to 2.22; 818 infants; one trial, moderate-quality evidence, respectively). Mean birthweight was lower in the induction group, but there was considerable heterogeneity between studies for this outcome (mean difference (MD) -178.03 g, 95% CI -315.26 to -40.81; 1190 infants; four studies; I2 = 89%).  For outcomes assessed using GRADE, we based our downgrading decisions on high risk of bias from lack of blinding and imprecision of effect estimates. AUTHORS' CONCLUSIONS: Induction of labour for suspected fetal macrosomia has not been shown to alter the risk of brachial plexus injury, but the power of the included studies to show a difference for such a rare event is limited. Also antenatal estimates of fetal weight are often inaccurate so many women may be worried unnecessarily, and many inductions may not be needed. Nevertheless, induction of labour for suspected fetal macrosomia results in a lower mean birthweight, and fewer birth fractures and shoulder dystocia. The observation of increased use of phototherapy in the largest trial, should also be kept in mind. Findings from trials included in the review suggest that to prevent one fracture it would be necessary to induce labour in 60 women. Since induction of labour does not appear to alter the rate of caesarean delivery or instrumental delivery, it is likely to be popular with many women. In settings where obstetricians can be reasonably confident about their scan assessment of fetal weight, the advantages and disadvantages of induction at or near term for fetuses suspected of being macrosomic should be discussed with parents. Although some parents and doctors may feel the evidence already justifies induction, others may justifiably disagree. Further trials of induction shortly before term for suspected fetal macrosomia are needed. Such trials should concentrate on refining the optimum gestation of induction, and improving the accuracy of the diagnosis of macrosomia.

Increased incidence of shoulder dystocia but a declining incidence of obstetric brachial plexus palsy in vaginally delivered infants.

INTRODUCTION: Obstetric brachial plexus palsy (OBPP) is a serious form of neonatal morbidity. The primary aim of this population-based registry study was to examine temporal trends, 1997-2019, of OBPP in infants delivered vaginally in a cephalic presentation. The secondary aim was to examine temporal changes in the incidence of associated risk factors. MATERIAL AND METHODS: This was a population-based registry study including singleton, cephalic, vaginally delivered infants, 1997-2019, in Sweden. To compare changes in the incidence rates of OBPP and associated risk factors over time, univariate logistic regression was used and odds ratios (OR) with 95% confidence intervals (CI) were calculated. RESULTS: The incidence of OBPP in infants delivered vaginally in a cephalic presentation decreased from 3.1 per 1000 births in 1997 to 1.0 per 1000 births in 2019 (OR 0.31, 95% CI 0.24-0.40). Conversely, the incidence of shoulder dystocia increased from 2.0 per 1000 in 1997 to 3.3 per 1000 in 2019 (OR 1.64, 95% CI 1.34-2.01). Over time, the proportion of women with body mass index of 30 kg/m2 or greater increased (14.5% in 2019 compared with 8.0% in year 1997, OR 1.96, 95% CI 1.89-2.03), more women had induction of labor (20.5% in 2019 compared with 8.6% in 1997, OR 2.74, 95% CI 2.66-2.83) and epidural analgesia (41.2% in 2019 compared with 29.0% in 1997, OR 1.72, 95% CI 1.68-1.75). In contrast, there was a decrease in the rate of operative vaginal delivery (6.0% in 2019, compared with 8.1% in 1997, OR 0.72, 95% CI 0.69, 0.75) and in the proportion of infants with a birthweight greater than 4500 g (2.7% in 2019 compared with 3.8% in 1997, OR 0.70, 95% CI 0.66-0.74). The decline in the incidence of these two risk factors explained only a small fraction of the overall decrease in OBPP between 1997-2002 and 2015-219. CONCLUSIONS: The incidence of OBPP in vaginally delivered infants in a cephalic presentation at birth decreased during the period 1997-2019 despite an increase in important risk factors including shoulder dystocia.

Factors associated with fear of childbirth in a subsequent pregnancy: a nationwide case-control analysis in Finland.

BACKGROUND: Fear of childbirth can develop due to the concerns or adverse maternal or foetal outcomes experienced in a previous pregnancy. The aim of this study was to examine the main risk factors associated with the development of fear of childbirth during subsequent pregnancies and deliveries. METHODS: In this case-control study, data from the National Medical Birth Register were used to evaluate the events in previous pregnancies that were potential risk factors for fear of childbirth in subsequent pregnancies. The first and second pregnancies of women registered during our study period (2004-2018) were included. The exposure variable was delivery mode, obstetric challenge or adverse neonatal outcomes during the first pregnancy. The outcome was the development of FOC during the second pregnancy. Adjusted odds ratios with 95% CIs were used for comparison. RESULTS: A total of 13 064 pregnancies were included in the case group and 195 351 in the control group. Previous emergency caesarean section was the strongest risk factor for the development of FOC in the second pregnancy (adjusted odds ratio 5.27, CIs 4.83-5.75). In addition, unplanned CS (adjusted odds ratio 3.93, CIs 3.77-4.10) and vacuum delivery (adjusted odds ratio 1.69, CIs 1.61-1.77) also increased the odds of fear of childbirth. Of the obstetric complications, third- or fourth-degree tear of the perineum was the strongest risk factor (adjusted odds ratio 2.99, CIs 2.69-3.31), followed by shoulder dystocia (adjusted odds ratio 2.82, CIs 2.16-3.62). Neonatal mortality also increased the odds for the development of FOC (adjusted odds ratio 2.17, CIs 1.77-2.64). CONCLUSION: The main risk factors for the development of fear of childbirth in the second pregnancy were previous fear of childbirth, unplanned CS, vacuum delivery, perineal tear or shoulder dystocia. The results of this study can be used in a clinical setting to improve the prevention of fear of childbirth.

Incidence changes in risk factors associated with the decreasing number of birth-related clavicle fractures in Finland: A nationwide retrospective birth cohort from 2004 to 2017.

BACKGROUND: A clavicle fracture is one of the most common birth injuries. The objective of this study was to examine whether the decreased incidence of birth-related clavicle fractures in Finland is because of temporal changes in their predisposing factors. METHODS: For this nationwide population-based study, we used the Finnish Medical Birth Register and the Care Register for Health Care databases. The study population included all singleton, live-born newborn born spontaneously or by vacuum-assisted delivery, in cephalic presentation ≥37+0 weeks of gestation. The incidences of clavicle fractures, pregnancy characteristics, and risk assessments for fracture were calculated and compared between two time periods: 2004-2010 and 2011-2017. RESULTS: A total of 629 457 newborn were born vaginally between 2004 and 2017. The clavicle fracture incidence decreased from 17.6/1000 to 6.2/1000 live births. Shoulder dystocia, diabetes, and birthweight ≥4000 g were the strongest predisposing factors. The incidence of birthweight ≥4000 g decreased, meanwhile type 1 diabetes and shoulder dystocia remained stable and gestational diabetes, type 2 diabetes, and maternal obesity increased in the later study period. The incidence of clavicle fractures without known predisposing factors declined. Simultaneously, the cesarean birth rate remained stable (13.2%-13.1%), although the rate of vacuum-assisted deliveries increased (8.5%-9.5%). DISCUSSION: The incidence of clavicle fractures decreased, even though the incidence of most risk factors remained stable or increased, and the cesarean birth rate remained stable. This decline may be related to the reduction of fracture incidence among deliveries without known risk factors, and the decrease in birthweight ≥4000 g.

Investigating the association factors of acute postpartum pain: a cohort study.

BACKGROUND: Labor pain intensity is known to predict persistent postpartum pain, whereas acute postpartum pain may interfere with maternal postpartum physical, mental, and emotional well-being. Nevertheless, there is little research studying the association between labor pain intensity and acute postpartum pain. This study investigated the associations between labor pain intensity and psychological factors with acute postpartum pain. METHODS: We included women with American Society of Anesthesiologists (ASA) physical status II, having ≥ 36 gestational weeks and a singleton pregnancy. We investigated the association between labor pain intensity (primary exposure) and high acute postpartum pain at 0 to 24 h after delivery (Numeric Rating Scale (NRS) ≥ 3 of 10; primary outcome). Pre-delivery questionnaires including Angle Labor Pain Questionnaire (A-LPQ), Pain Catastrophizing Scale (PCS), Fear Avoidance Components Scale (FACS) and State Trait Anxiety Inventory (STAI) were administered. Demographic, pain, obstetric and neonatal characteristics were also collected accordingly. RESULTS: Of the 880 women studied, 121 (13.8%) had high acute postpartum pain at 0 to 24 h after delivery. A-LPQ total, PCS, FACS and STAI scores were not significantly associated with acute postpartum pain. Greater A-LPQ subscale on birthing pain (adjusted odds ratio (aOR) 1.03, 95% CI 1.01-1.05, p = 0.0008), increased blood loss during delivery (for every 10ml change; aOR 1.01, 95% CI 1.00-1.03, p = 0.0148), presence of shoulder dystocia (aOR 10.06, 95% CI 2.28-44.36, p = 0.0023), and use of pethidine for labor analgesia (aOR 1.74, 95% CI 1.07-2.84, p = 0.0271) were independently associated with high acute postpartum pain. "Sometimes" having nausea during menstruation before current pregnancy (aOR 0.34, 95% CI 0.16-0.72, p = 0.0045) was found to be independently associated with reduced risk of high acute postpartum pain. CONCLUSIONS: Pre-delivery pain factor together with obstetric complications (shoulder dystocia, blood loss during delivery) were independently associated with high acute postpartum pain. TRIAL REGISTRATION: This study was registered on clinicaltrials.gov registry (NCT03167905) on 30/05/2017.