Sunday, September 26, 2021

Shoulder Dystocia Case File

Posted By: Medical Group - 9/26/2021 Post Author : Medical Group Post Date : Sunday, September 26, 2021 Post Time : 9/26/2021
Shoulder Dystocia Case File
Eugene C. Toy, MD, Edward Yeomans, MD, Linda Fonseca, MD, Joseph M. Ernest, MD

Case 26
A 28-year-old G4P3 at 40 weeks’ gestation presents to labor and delivery in active labor and ruptured membranes. Her antenatal course was complicated by diet-controlled gestational diabetes. Her previous three pregnancies ended in vaginal delivery at term with the largest infant weighing 4000 g. She is 5 ft tall and weighs 220 lb. Fundal height was 42 cm, fetal heart tones (FHTs) were normal, and the EFW was 3800 g. The first stage of labor was uneventful, but after just 10 minutes of the second stage, the fetal head delivered and promptly retracted against the vulva (positive turtle sign). Normal traction by the operator did not result in delivery of the anterior shoulder.

➤ What is the most likely diagnosis?
➤ What is your next step?
➤ What are the potential complications for mother and baby in this situation?

Shoulder Dystocia

Summary: An obese, parous gestational diabetic was admitted in active labor. Following a very short second stage, the head delivered but the anterior shoulder became impacted behind the symphysis pubis.

Most likely diagnosis: Shoulder dystocia.

Next step: Initiate a well-planned sequence of maneuvers1 (see following discussion) designed to accomplish delivery of the infant.

Potential complications: Maternal—third or fourth degree laceration or extension of an episiotomy. Neonatal—fractures of clavicle or humerus, brachial plexus injury, asphyxia, stillbirth.

  1. Be able to recognize the most common risk factors for shoulder dystocia.
  2. Appreciate that most risk factors for shoulder dystocia have very low positive predictive value.
  3. Develop a personal algorithm for the management of shoulder dystocia.
  4. Understand the importance of simulation training, shoulder dystocia drills, and thorough documentation of the event in the patient’s medical record.

The patient in the case scenario has multiple risk factors for shoulder dystocia including multiparity, obesity, gestational diabetes, and a precipitous second stage of labor. A short second stage may not allow sufficient time for the shoulders of the infant to accommodate to the bony pelvis. Despite the presence of well-recognized individual risk factors for shoulder dystocia, at least 50% of cases have no known risk factors. The most common risk factors for shoulder dystocia are listed in Table 26–1.

In this case, the time between delivery of the head and delivery of the body (head-to-body interval or HBI) is critical since adverse neonatal outcomes correlate with increasing time on the perineum.2 For obstetricians of widely varying experience, shoulder dystocia represents a true emergency, exemplified by the words of Woods, for whom a secondary but occasionally life-saving maneuver is named: “Very few of our mechanical problems in obstetrics


Postterm pregnancy
Prolonged second stage
Midpelvic instrumental delivery
Precipitous labor
Previous delivery complicated by shoulder dystocia
Weight gain during pregnancy

require emergency treatment. Difficulty in delivery of the shoulders, however, usually comes as a complete surprise. We have no warning, a real emergency exists, and the minutes we have in which to make a safe delivery usually pass much faster than expert help can arrive.”3

Shoulder Dystocia


SHOULDER DYSTOCIA: Failure of normal downward traction to deliver the anterior shoulder. Additional maneuvers therefore become necessary. Some investigators use a head-to-body interval of greater than 1 minute as a definition.2

McROBERTS MANEUVER: Flexion of the maternal hips followed by abduction of the thighs, thereby rotating the pubic symphysis cephalad and straightening the lumbosacral angle.

WOODS MANEUVER: Abduction of the posterior shoulder by pressure on its ventral surface to accomplish rotation.3 The original description of this maneuver included the application of fundal pressure once the shoulders were rotated, but fundal pressure is no longer advocated.

BARNUM MANEUVER: Delivery of the posterior arm, described more than 60 years ago by Barnum. Some authors have recommended assigning this maneuver to a higher priority in the management algorithm for shoulder dystocia.4


In the case presented, shoulder dystocia was associated with a very short second stage (“precipitous” delivery). This is one circumstance where it might be indicated to allow a little more time for the shoulders to rotate to the more favorable oblique diameter of the pelvis. In all other shoulder dystocia cases, the practitioner would be well-served to take a few seconds to assess, digitally, whether the anterior shoulder is impacted behind the symphysis and whether the posterior shoulder occupies the sacral hollow. Even though time is critical, as previously mentioned, the time is measured in minutes, not seconds. Excessive anxiety over failure of the shoulders to deliver immediately after the head may actually contribute to rather than resolve problems. The fetal head retracting back toward the perineum (turtle sign) is commonly encountered, see Figure 26–1.

Once the diagnosis of shoulder dystocia is evident, every obstetric provider should initiate a personal algorithm for managing the dystocia. Published evidence does not support the existence of a single “best practice” approach. Therefore, a brief description of several commonly used maneuvers follows, without championing a preferred order of employing these maneuvers.

McRoberts maneuver (see definitions) was described in 1983, but likely used before that.5 Because it led to delivery without additional maneuvers in

Shoulder dystocia with turtle sign

Figure 26–1. Shoulder dystocia with turtle sign. (Reproduced, with permission, from
Knoop KJ,Stack LB,Storrow AB,et al.Atlas of Emergency Medicine. 3rd ed.New York,NY:
McGraw-Hill; 2010:259. Photo contributor: William Leninger,MD.)

a fair number of cases, it was very popular in the decade or two following its description. Evidence that its use lowers the prevalence of brachial plexus injuries is lacking, however. MacKenzie and colleagues6 reported that of 20 cases of brachial plexus injuries, 19 were managed with the McRoberts maneuver. It must be remembered that once the woman has been placed in McRoberts position, the next step is still traction and that traction may still be excessive. Further, it is not necessary to simultaneously apply suprapubic pressure with McRoberts maneuver. Instead, suprapubic pressure, correctly applied in a direction that leads to adduction of the anterior shoulder should be regarded as a separate intervention in the algorithm. 

The Rubin maneuver consists of finger pressure to the anterior or posterior shoulder to produce adduction. This maneuver is designed to reduce the bisacromial diameter of the fetus. It should be combined with oblique traction in the axis of the shoulders rather than direct anteroposterior traction. 

The Barnum maneuver involves delivery of the posterior arm of the fetus (see Definitions). At least one group has recommended that this be considered as an initial maneuver, but executing the maneuver is often technically difficult, especially with limited room in the vagina. On occasion, difficulty in delivery may still be encountered after successful delivery of the posterior arm. 

The Woods maneuver is no longer performed as it was originally described. Fundal pressure has been eliminated and pressure is sometimes placed on the posterior rather than the anterior aspect of the posterior shoulder (see Figure 26–2). The goal of this maneuver is to move the impacted anterior shoulder from behind the symphysis utilizing the rotational principle of a screw. Thus, the maneuver is sometimes referred to as the Woods screw or the Woods corkscrew maneuver. 

Clearly, the maneuvers described above are just a few of the many that have been suggested for managing shoulder dystocia. Other potentially useful maneuvers include the Gaskin (all-fours) maneuver, Zavanelli maneuver, symphysiotomy, intentional clavicular fracture, suprapubic pressure, and the recently described posterior axillary sling traction.7 Not all of these maneuvers are strongly recommended, and maternal and neonatal complications may be attributable to their use. However, in the worst of dystocias, knowing about these unusual maneuvers and how to perform them may be lifesaving for the infant. Whatever the sequence employed, and whether the sequence is repeated by the same or a more experienced provider, injury to the brachial plexus is not always preventable, nor is it always an indication of improper delivery technique. There is convincing evidence that brachial plexus injury can occur without shoulder dystocia.8 

The frequency of shoulder dystocia has been reported to be between 2/1000 and 2/100 deliveries. Because it is uncommon, unpredictable, and potentially catastrophic, there has been much emphasis on shoulder dystocia drills and simulation training.9 Such training fosters recognition of the need to call for help, the importance of teamwork, practice executing the various maneuvers

Woods maneuver

Figure 26–2. The figure illustrates the modified Woods maneuver.The hand is placed
behind the posterior shoulder of the fetus. The shoulder is then rotated progressively
180 degrees in a corkscrew manner so that the impacted anterior shoulder is
released. (Reproduced, with permission, from Cunningham FG, Leveno KJ, Bloom SL, et al.
Williams Obstetrics. 23rd ed.New York,NY: McGraw-Hill; 2010.)

and, perhaps most importantly, facilitates teaching in a controlled rather than an emergency environment. Simulation training also provides an opportunity to practice documentation of delivery-related events10 (see Table 26–2). 

Experience has shown that prevention of shoulder dystocia is not an achievable goal. Therefore, it is incumbent on everyone who delivers babies to optimize their management of this obstetric emergency. Calm execution of a carefully rehearsed personal management algorithm should enable providers to minimize the occurrence of catastrophic outcomes including permanent brachial plexus injury, hypoxic brain injury, and stillbirth resulting from failure to deliver in a reasonable period of time.

shoulder dystocia record

Comprehension Questions

26.1 What head-to-body interval has been used to define shoulder dystocia?
A. 25 seconds
B. 1 minute
C. 3 minutes
D. 5 minutes

26.2 Extraction of the posterior arm is known as what maneuver?
A. McRoberts
B. Rubin
C. Barnum
D. Woods

26.3 What percentage of shoulder dystocias are complicated by neonatal brachial plexus injuries?
A. 5%
B. 15%
C. 30%
D. 50%


26.1 B. The head-to-body interval is 25 seconds in a normal delivery. Shoulder dystocia is defined by some as a head-to-body interval of 1 minute. Deliveries that take 3 to 5 minutes or even longer are associated with increased neonatal adverse outcomes.

26.2 C. The McRoberts maneuver involves repositioning the mother. The Rubin maneuver is designed to disimpact the anterior shoulder from behind the symphysis. The Woods maneuver is a rotational maneuver that utilizes the principle of a screw. The Barnum maneuver advocates extraction of the posterior arm of the fetus over the perineum, substituting a smaller diameter for the arrested bisacromial diameter.

26.3 B. Although the incidence of brachial plexus injuries varies in different reports, 15% is the best answer among the choices provided. Less than 10% of brachial plexus injuries resulting from shoulder dystocia are permanent.

Clinical Pearls

See US Preventive Services Task Force Study Quality levels of evidence in Case 1
➤ When faced with a shoulder dystocia, call for additional help (Level III).
➤ Although most dystocias are due to obstruction by the bony pelvis,proper maternal position and episiotomy may facilitate delivery (Level III).
➤ Be alert for newly described techniques to add to your personal algorithm for shoulder dystocia management (Level III).
➤ Develop a conviction that you will get the baby out. Injury is preferable to stillbirth (Level III).


1. Gherman RB, Ouzounian JG, Goodwin TM. Obstetric maneuvers for shoulder dystocia and associated fetal morbidity. Am J Obstet Gynecol. 1998;178:1126-1130. 

2. Beall MH, Spong C, McKay J, Ross MG. Objective definition of shoulder dystocia: a prospective evaluation. Am J Obstet Gynecol. 1998;179(4):934-937. 

3. Woods CE. A principle of physics as applicable to shoulder delivery. Am J Obstet Gynecol. 1943;45:796-804. 

4. Poggi SH, Spong CY, Allen RH. Prioritizing posterior arm delivery during severe shoulder dystocia. Obstet Gynecol. 2003;101:1068-1072. 

5. Gurewitsch ED. Optimizing shoulder dystocia management to prevent birth injury. Clin Obstet Gynecol. 2007;50:592-606. 

6. MacKenzie IZ, Shah M, Lean K, Dutton S, Newdick H, Tucker, DE. Management of shoulder dystocia. Obstet Gynecol. 2007;110:1059-1068. 

7. Cluver CA, Hofmeyr GJ. Posterior axilla sling traction: a technique for intractable shoulder dystocia. Obstet Gynecol. 2009;113:486-488. 

8. Doumouchtsis SK, Arulkumaran S. Are all brachial plexus injuries caused by shoulder dystocia? Obstet Gynecol Surv. 2009 Sep;64(9):615-623. 

9. Crofts JF, Fox R, Ellis D, Winter C, Hinshaw K, Draycott TJ. Observations from 450 shoulder dystocia simulations. Obstet Gynecol. 2008;112:906-912. 

10. Deering S, Poggi S, Hodor J, Macedonia C, Satin AJ. Evaluation of residents’ delivery notes after a simulated shoulder dystocia. Obstet Gynecol. 2004;104:667-670.


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