incidence of shoulder dystocia among vaginal deliveries e Practice Bulletin Shoulder Dystocia .. these resources at –Info/Shoulder. Along with the American College of Obstetricians and Gynecologists (ACOG) practice bulletin on shoulder dystocia, guidelines from England, Canada, Australia. Request PDF on ResearchGate | On Feb 1, , Robert J Sokol and others published ACOG practice bulletin: Shoulder dystocia. Number 40, November
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Obstetricians have two major concerns when dealing with shoulder dystocia. The first is the technical aspects of attempting to predict who is at risk for shoulder dystocia, managing it when it occurs, and attempting to avoid the dreaded consequence of permanent brachial plexus injury to the neonate during its resolution.
The second concern is the ever-present fear in the mind of every practicing obstetrician that if a baby is injured during a shoulder dystocia delivery, rightly or wrongly the obstetrician will be held to be at fault in the lawsuit that will almost certainly follow. Shoulder dystocia occurs when there is an inability to deliver a baby’s shoulders after its head has emerged.
In such cases, the baby’s shoulder has become impacted behind the mother’s pubic symphysis Figure 1. The official American Congress of Obstetricians and Gynecologists ACOG definition of a shoulder dystocia delivery is one that requires additional obstetrical maneuvers following thefailure of gentle downward traction on the fetal head to effect delivery of the shoulders.
It is thought that when a neonate’s shoulders get stuck during a shoulder dystocia delivery, it is because instead of the shoulders descending into the wider oblique diameter of the maternal pelvic outlet, the shoulders instead descend in an anterior-posterior orientation.
This diameter is narrower than the oblique diameter, increasing the chances that the baby’s anterior shoulder will get stuck behind the maternal symphysis. This prevents the normal sequence of prompt delivery of the shoulders following that of the head. However, some authors have not found the ACOG definition sufficiently reproducible or quantifiable to be useful.
Spong et al have defined shoulder dystocia as a prolonged head-to-body delivery time e. In the Spong study, 60 seconds was found to be approximately two standard deviations above the mean value for head-to-body delivery time in uncomplicated shoulder dystocia deliveries.
The incidence of shoulder dystocia is 0. This incidence has risen over the last decade, largely due to the almost epidemic national increase in maternal obesity, a major risk factor for fetal macrosomia.
Yet, some of this observed increase is no doubt due to better reporting as awareness among obstetricians of the importance of proper documentation of shoulder dystocias has increased. While many factors have been cited as increasing the risk for shoulder dystocia, careful analysis shows that there are only four primary risk factors:. All other supposed risk factors for shoulder dystocia turn out to merely be markers in one form or another of the above.
There is a direct linkage between birth weight and the risk of shoulder dystocia. This has been demonstrated repeatedly in innumerable studies over multiple decades. The data in Table I correlating birth weight with shoulder dystocia from a large university-affiliated obstetrical service are representative. Most other proposed risk factors for shoulder dystocia exert their influence because of their association with increased birth weight. Despite this clear linkage between fetal macrosomia and shoulder dystocia, there are significant problems with clinicians attempting to use suspected fetal macrosomia to predict which patients will experience shoulder dystocia at delivery:.
The ability to accurately predict fetal weight prior to delivery is notoriously poor. Some studies have shown that clinical estimates of fetal weight by palpation are more accurate than are ultrasound estimates.
ACOG Practice Bulletin # Shoulder Dystocia
Definitions of macrosomia are not consistent, either in clinical practice or in the obstetrical literature. Moreover, many other textbooks and papers discuss 4, g and 4, g, respectively, as weights at which to “consider” recommending a cesarean section.
Approximately half of all shoulder dystocias occur with newborns weighing less than 4, g, below anybody’s definition of macrosomia. Estimating fetal weight in order to attempt to prevent shoulder dystocias by doing elective cesarean sections would result in the performance of thousands of cesarean sections—with all their inherent risks—to prevent a single permanent brachial plexus injury. In babies of diabetic mothers, the risk of shoulder dystocia in any weight group is 2.
Additionally, the incidence and severity of neonatal injury from shoulder dystocia is higher in babies born of diabetic mothers Table II.
The reason for the increased risk of shoulder dystocia in these babies has to do with their different growth morphology compared with babies of nondiabetic mothers. Given equal weights, babies born of diabetic mothers have larger shoulders, chest circumference, and abdominal circumference than those born of nondiabetic mothers.
Although tight maternal blood sugar control during pregnancy does not eliminate the risk disparity between babies of mothers with gestational diabetes and those without, tight control has been shown to reduce the risk of fetal macrosomia, shoulder dystocia, and neonatal injury.
Moreover, there is a higher rate of injury and severity of injury in newborns whose delivery represents a recurrent shoulder dystocia.
Yet, while many clinicians recommend cesarean section for delivery of a pregnant patient who has had a previous shoulder dystocia delivery, the effectiveness of this policy in reducing risk is not clear. The ACOG Practice Bulletin on Shoulder Dystocia says, “because most subsequent deliveries will not be complicated by shoulder dystocia, the benefit of universal elective cesarean delivery is questionable in patients who have such a history of shoulder dystocia.
Deliveries requiring mid vacuum or forceps result in rates of shoulder dystocia that are 4. This ratio is even higher if both vacuum and forceps are used sequentially. However, there is little information in the published literature on the contribution that low vacuum and low forceps deliveries—especially outlet interventions—make to the incidence of shoulder dystocia. There are a limited number of proven risk factors for shoulder dystocia. Most “risk factors” exert their influence because of an association with increased birth weight.
Most women who experience shoulder dystocia have no combination of risk factors that allows bluletin useful prediction prior to delivery.
Patients who have true risk factors for shoulder dystocia—suspected macrosomia, gestational diabetes, a history of a previous shoulder dystocia— must be counseled about their increased risk for shoulder dystocia, and this conversation must be documented in the medical record.
Although shoulder dystocia is, in most bullletin, unpredictable and unpreventable, there are certain precautions that can be taken which will enable you to be best prepared ehoulder it does occur:. Perform a routine “shoulder dystocia review” at or around 36 weeks gestation looking for:. If any risk factors are present, counsel your patient about this risk and document this conversation in the medical record. Simulation drills for shoulder dystocia—and other infrequent obstetrical emergencies—are vital.
The only props needed are a pelvic model and a doll. There are seven aspects to management of shoulder dystocia emergencies, each of which is vitally important in increasing the chances of a safe, successful outcome:. When a clinician suspects that there is an increased risk of shoulder dystocia in a given patient, he or she should do the following:.
Notify both the labor nurse and the supervising charge nurse of the increased risk of shoulder dystocia with this delivery. Make certain that a step stool is available to allow an assistant to provide suprapubic pressure at the correct angle. A shoulder dystocia presents with the inability of the anterior fetal shoulder to emerge from the vagina with maternal pushing and routine physician traction after shoukder of the head.
It is often preceded by the turtle sign. The clinician must promptly recognize this as a shoulder dystocia and immediately do the following:. Have the mother stop pushing and cease traction if one or two such efforts are not successful in delivering the shoulder.
Alert medical personnel in the room to the presence of a shoulder dystocia. Ask that extra nursing staff, a pediatrician, an anesthesiologist, and another obstetrician be called to assist. Briefly explain to the patient that the baby’s shoulders are “temporarily stuck” and that you and bullwtin team will be working to get the baby out safely.
Begin the series of shoulder dystocia resolution maneuvers in a calm, deliberate, yet time-sensitive fashion. Make the management of this emergency as deliberate and efficient as possible. By default, you will immediately become the leader of what must instantly become a high-performance team.
Provide clear and firm direction. Avoid an inappropriate sense of urgency while at the same time recognizing that you have somewhere between 6 to 10 minutes before central ackg damage is likely to occur. Assign one staff member to be a timekeeper and scribe. This person should call out loud each second interval that passes so that the team is constantly aware of the duration of the shoulder dystocia.
Such knowledge helps the obstetrician in charge bullletin modulate the pace of shoulder dystocia resolution maneuvers and to know when an increase in the intensity of delivery efforts may be appropriate.
The McRoberts maneuver Figure 2 is the most commonly used shoulder dystocia resolution maneuver. It involves flexing the maternal thighs up against the mother’s chest. The McRoberts positioning works not by changing the actual dimensions of the maternal pelvis, but by straightening out the sacrum relative to the lumbar spine.
This allows cephalic rotation of the synthesis pubis, enabling the fetal shoulder to slide under it. The McRoberts maneuver is almost always used in conjunction with suprapubic pressure. Suprapubic pressure Figure 3 is pressure applied just above the maternal symphysis pubis to the anterior shoulder of the fetus.
The goal of this maneuver is to move the fetal shoulder away from its direct anterior-posterior orientation in the maternal pelvis into an oblique position. Suprapubic pressure must be distinguished from fundal pressure, in which downward pressure is applied to the top of the uterus. Fundal pressure serves only to drive the impacted shoulder further into a nondeliverable position, and should never be employed in the context of a shoulder dystocia.
Episiotomies are only useful if there is insufficient room in the vagina for the clinician to put his or her hand inside to perform necessary maneuvers.
Shoulder dystocia results from a misfit between the fetal shoulder and the boney pelvis; it is not a soft-tissue dystocia. Episiotomies in and of themselves do not aid in the resolution of shoulder dystocia. These maneuvers are variations of ways of rotating the fetal shoulders in order to change their orientation in the maternal pelvis.
In the Wood’s corkscrew maneuver Figure 4the anterior surface of either uppr or lower fetal shoulder is pushed by the deliverer’s hand in an effort to “torque” the baby out of the vagina.
In Rubin’s maneuver Figure 4the posterior aspect of either shoulder is pushed. The Rubin’s approach has the added benefit of “flexing” the shoulders, bringing them closer dystovia and thus decreasing the biacromial diameter. It is not particularly important whether it is the anterior or posterior shoulder or its front or back surface that is pushed during rotational maneuvers. The clinician should grasp practide shoulder is most easily reached dysgocia push it in whichever direction the fetus turns most easily.
High rates of success have been reported with the use of rotational maneuvers to resolve shoulder dystocias. The hand or arm is then swept across the fetal chest and delivered.
Rpactice the entire arm and shoulder are exteriorized, it is easy to rotate the baby so as to free up the stuck anterior shoulder.
The remainder of the baby delivers without difficulty. While other maneuvers to resolve shoulder dystocia are described, they are rarely employed, either because of their high rate of practicf or the difficulty of performing them Table IV. While cutting the nuchal cord after delivery of the head is often routine, doing so in the context of a shoulder dystocia may prove fatal.
Umbilical cord transection may prevent even minimal blood flow to the baby throughout the duration of the dystocia.
Before cutting an umbilical cord, the deliverer must be very certain that the entire baby will emerge within seconds thereafter.
Being able to document whether there was in fact real asphyxia at birth and whether there was a base deficit—indicative of longer-term asphyxia—can provide important information both as to the baby’s status and as a refutation to later claims of inappropriate care. Have a discussion with the family about the events that transpired—and document this conversation. Family and friends observing the delivery see a relatively calm labor room erupt into a frenzy of activity with voices cystocia tense and multiple medical practitioners coming and going.
At delivery, the baby may temporarily appear blue and not cry. Inexperienced observers often draw a host of erroneous impressions hsoulder to what has happened in such a situation. It is vital, therefore, for the delivering clinician to make time to sit and talk to the family and friends after the delivery and to explain what really transpired and why.