Epidemiologic aspects of shoulder dystocia-related neurological birth injuries

Shoulder dystocia and composite adverse outcomes for the maternal-neonatal dyad

BACKGROUND

Although the neonatal morbidity associated with shoulder dystocia are well known, the maternal morbidity caused by this obstetrical emergency is infrequently reported.

OBJECTIVE

This study aimed to assess the composite adverse maternal and neonatal outcomes among vaginal deliveries (at 34 weeks or later) with and without shoulder dystocia.

STUDY DESIGN

This is a secondary analysis of the Consortium of Safe Labor, an observational obstetrical cohort of all vaginal deliveries occurring at 19 hospitals (from 2002-2008) and for which data on the occurrence of shoulder dystocia were available. The composite adverse maternal outcome included third- or fourth-degree perineal laceration, postpartum hemorrhage (>500 cc blood loss for a vaginal delivery and >1000 cc blood loss for cesarean delivery), blood transfusion, chorioamnionitis, endometritis, thromboembolism, admission to intensive care unit, or maternal death. The composite adverse neonatal outcome included an Apgar score of <7 at 5 minutes, a birth injury, neonatal seizure, hypoxic ischemic encephalopathy, or neonatal death. A multivariable Poisson regression was used to estimate the adjusted relative risks with 95% confidence intervals. The area under the receiver operating characteristic curve was constructed to determine if clinical factors would identify shoulder dystocia.

RESULTS

Of the 228,438 women in the overall cohort, 130,008 (59.6%) met the inclusion criteria, and among them, shoulder dystocia was documented in 2159 (1.7%) cases. The rate of composite maternal morbidity was significantly higher among deliveries with shoulder dystocia (14.7%) than without (8.6%; adjusted relative risk, 1.71; 95% confidence interval, 1.64-2.01). The most common maternal morbidity with shoulder dystocia was a third- or fourth-degree laceration (adjusted relative risk, 2.82; 95% confidence interval, 2.39-3.31). The risk of composite neonatal morbidity with shoulder dystocia (12.2%) was also significantly higher than without shoulder dystocia (2.4%) (adjusted relative risk, 5.18; 95% confidence interval, 4.60-5.84). The most common neonatal morbidity was birth injury (adjusted relative risk, 5.39; 95% confidence interval, 4.71-6.17). The area under the curve for maternal characteristics to identify shoulder dystocia was 0.66 and it was 0.67 for intrapartum factors.

CONCLUSION

Although shoulder dystocia is unpredictable, the associated morbidity affects both mothers and newborns. The focus should be on concurrently averting the composite morbidity for the maternal-neonatal dyad with shoulder dystocia.

Rising trends in the incidence of shoulder dystocia and development of a novel shoulder dystocia risk score tool: a nationwide population-based study of 800 484 Finnish deliveries

INTRODUCTION

Shoulder dystocia has remained an unpredictable and feared emergency in obstetrics. Some risk factors have been identified but nevertheless there is a lack of risk evaluation tools in clinical practice. The aim of this study was to evaluate the incidence and risk factors of shoulder dystocia in the Finnish population and to develop a shoulder dystocia risk score tool.

MATERIAL AND METHODS

This retrospective, population-based study included all deliveries in Finland between 2004 and 2017 (n = 800 484). The annual numbers of shoulder dystocia diagnoses were gathered from nationwide Finnish Medical Birth Register and Hospital Discharge Register. The incidence of shoulder dystocia was calculated in subgroups according to the mode of delivery, maternal diabetes status, body mass index (BMI), age, parity and gestational age. Based on these numbers, a shoulder dystocia risk score tool was created.

RESULTS

The overall incidence of shoulder dystocia was 0.18%. It increased significantly during the study period from 0.10% to 0.32% (P < .001). More specifically, the incidence increased significantly in all analyzed subgroups except for women with BMI <18.5 or age <20 years. To evaluate the importance of risk factors, practical and simple shoulder dystocia risk score tool was created. Instrumental vaginal delivery, maternal diabetes of any kind, BMI ≥25, age ≥40 years and gestational age ≥41 weeks were associated with higher shoulder dystocia risk compared with non-diabetic, non-obese and younger women with spontaneous deliveries before 41 weeks of gestation. In our risk score tool, cases with shoulder dystocia had a significantly higher number of risk points than those without it (15.2 vs 10.4, P < .001). The risk was significantly high when the scores were ≥18 points (relative risk 9.54, 95% confidence interval 8.61-10.57).

CONCLUSIONS

The incidence of shoulder dystocia in Finland increased during the study period but it is still low compared with previous studies from other countries. In clinical daily practice, the new shoulder dystocia risk score tool helps to evaluate the individual risk profile of the parturient. According to this risk score tool, the highest risk was found with the combination of instrumental vaginal delivery, maternal diabetes, BMI ≥25, age ≥40 years and gestational age ≥41 weeks.

A Study of the Diagnostic Accuracy of an Existing Multivariable Test to Predict Shoulder Dystocia

Objectives  To evaluate the diagnostic accuracy of a multivariable prediction model, the Shoulder Screen (Perigen, Inc.), and compare it with the American College of Obstetricians and Gynecologists (ACOG) guidelines to prevent harm from shoulder dystocia. Study Design  The model was applied to two groups of 199 patients each who delivered during a 4-year period. One group experienced shoulder dystocia and the other group delivered without shoulder dystocia. The model's accuracy was analyzed. The performance of the model was compared with the ACOG guideline. Results  The sensitivity, specificity, positive, and negative predictive values of the model were 23.1, 99.5, 97.9, and 56.4%, respectively. The sensitivity of the ACOG guideline was 10.1%. The false-positive rate of the model was 0.5%. The accuracy of the model was 61.3%. Conclusion  A multivariable prediction model can predict shoulder dystocia and is more accurate than ACOG guidelines.

Prevention of shoulder dystocia: A randomized controlled trial to evaluate an obstetric maneuver

OBJECTIVE

Shoulder dystocia is a major obstetric emergency defined as a failure of delivery of the fetal shoulder(s). This study evaluated whether an obstetric maneuver, the push back maneuver performed gently on the fetal head during delivery, could reduce the risk of shoulder dystocia.

STUDY DESIGN

We performed a multicenter, randomized, single-blind trial to compare the push back maneuver with usual care in parturient women at term. The primary outcome, shoulder dystocia, was considered to have occurred if, after delivery of the fetal head, any additional obstetric maneuver, beginning with the McRoberts maneuver, other than gentle downward traction and episiotomy was required.

RESULTS

We randomly assigned 522 women to the push back maneuver group (group P) and 523 women to the standard vaginal delivery group (group S). Finally, 473 women assigned to group P and 472 women assigned to group S delivered vaginally. The rate of shoulder dystocia was significantly lower in group P (1·5%) than in group S (3·8%) (odds ratio [OR] 0·38 [0·16-0·92]; P = 0·03). After adjustment for predefined main risk factors, dystocia remained significantly lower in group P than in group S. There were no significant between-group differences in neonatal complications, including brachial plexus injury, clavicle fracture, hematoma and generalized asphyxia.

CONCLUSION

In this trial in 945 women who delivered vaginally, the push back maneuver significantly decreased the risk of shoulder dystocia, as compared with standard vaginal delivery.

Normal Range of Head-to-body Delivery Interval by Two-step Delivery

Background:

The one-step method was routine practices in China, scientific evidence to support this intervention is scarce. The purpose of this study was to observe the natural process of head-to-body delivery interval by waiting for at least one contraction (two-step) after head delivered in normal birth.

Methods:

From March 1 to March 30 in 2015 at Haikou Maternal and Child Hospital in China, normal vaginal birth with normal baby condition were recorded by video. Videotapes were transferred to computer then replayed and observed.

Results:

Ninety-two cases were enrolled in this study. The average head-to-body delivery interval by two-step delivery was 71.04 ± 61.02 s, (mean + 2 standard deviation = 193.07 s, 95% confidence interval [15.65–229.15] s). Fifty-one patients (51/92, 55.43%) were <60 s, 41 patients (41/92, 44.57%) were over 60 s. Shoulders delivered at the first contraction were 96.74% (89/92), 3.26% (3/92) had delivered by the second contraction. Shoulders emerged from perineum were 71.73% (66/92), 15.21% (14/92) transversely, and 13.04% (12/92) emerged from under pubic arch. Babies cried before the shoulder were 31.52% (29/92), cried after birth 52.17% (48/92), and 16.30% (15/92) did not cry after birth. Baby activities included as making faces, sucking, and bubbled from mouth and noses, and the lighter blue color of skin with good perfusion.

Conclusions:

The average time of head-to-body delivery interval was longer than 60 s by two-step delivery. Majority shoulders were delivered at the first contraction. Majority shoulders emerged from perineum rather from under pubic arch. The routine one-step method of shoulder delivery where the downward force applied is not necessary and is not the right direction. Baby's breath, making faces, sucking, bubble from noses and mouth, and the light blue color of the faces, all those signs during shoulder delivery indicated a normal live birth.

[The Jacquemier's maneuver: An overview of midwives knowledge and practices in a third level maternity hospital]

OBJECTIVES

Shoulder dystocia is an uncommon but serious complication occurring in 0.2 to 3% of deliveries. We carried out a study in order to assess the midwives experience, knowledge and practices on shoulder dystocia, at the maternity hospital of Saint-Denis, Reunion Island.

METHODS

The first part is a confidential questionnaire addressed to midwives working in the delivery unit. The second part is a retrospective desk review of shoulders dystocia which occurred from 2004 to 2014.

RESULTS

(1) The population was made up of 28 midwives, having between 1 to 27 years of experience. Seventy-five percent of them had been faced with shoulder dystocia, and 62% had realized Jacquemier's maneuver. However, only 25% received this maneuver training. Less than a third of them answered correctly to at least 7 from the 8 theoretical questions about the Jacquemier's maneuver. (2) We studied 34 shoulders dystocia, occurring between 36+5 to 41+2 gestational weeks, mostly with no risk factors found. Mac Roberts' maneuver is used as first-line in 88% of situations. Jacquemier's maneuver is used in 52.9% of cases (5.9% as first-line, 47% as second-line). In 26.4% of situations, the midwife is not able to reduce the dystocia. She usually carries out a combination of maneuvers. The gynecologist is asked only for 23.5% of dystocia and he usually uses Jacquemier's maneuver (70% of situations).

CONCLUSION

The Jacquemier's maneuver is rarely practiced (uncommon situation, lack of training). Simulation trainings should be put in place, because neonatal sequels can be avoided.