Shoulder Dystocia & Erb’s Palsy
(Brachial Plexus Injury) - Updated Information
Author: Edward J. Quilligan
Objectives: Upon the completion of this CNE article the reader will be able to:
1. Describe the
warning signs and risk factors surrounding shoulder dystocia and whether a
shoulder dystocia is predictable and thus preventable.
2. Explain the various maneuvers that may
be performed in relieving a shoulder dystocia.
3. Define the term brachial plexus injury
and discuss the relationship of this injury related to shoulder dystocia.
4. Describe the issues of informed consent
regarding shoulder dystocia and how brachial plexus injury can occur in
non-shoulder dystocia deliveries.
Shoulder dystocia is defined as a delivery in which the fetal
shoulders do not delivery following gentle (normal) downward traction on the
baby’s head that requires the use of additional obstetrical maneuvers to
complete the delivery. This article will discuss the topics listed below that
are related to this obstetrical emergency.
Incidence and general overview
Risk factors / potential warning signs /
Obstetrical maneuvers that can be utilized
Informed consent and scheduled cesarean section
Incidence and General Overview
the statistics of shoulder dystocia and Erb’s palsy is probably one of the most
important subject matters of this article. The overall incidence of shoulder
dystocia is approximately 1% of all deliveries. In studies, the rate varies
between about 0.2% to 3% depending on the definition for shoulder dystocia that
was used and the population studied.
What is true is that this rate increases as birthweight increases. On
average, the risk of shoulder dystocia is probably about 0.5 % for births under
4000 grams, 2% to 3% for births between 4000 and 4500 grams, and 4% to 15% for
births greater than 4500 grams.
though the risk for shoulder dystocia is greater in births over 4000 grams, the
overall number of shoulder dystocia deliveries is about 50/50 for births under
4000 grams and births over 4000 grams. This is because 85% to 90% of all births
result in babies that are less than 4000 grams. This is an important fact when
we discuss the predictability of shoulder dystocia later on in this article.
incidence of brachial plexus injury is somewhat different. It is important to
understand that most shoulder dystocia deliveries do not result in Erb’s palsy.
Likewise, approximately half of the Erb’s palsies that are seen come from
deliveries in which there was no shoulder dystocia. This is a fact that needs
to be understood. For years, nearly every textbook in obstetrics and pediatrics
stated that if a baby was found to have an Erb’s palsy following birth, then a
shoulder dystocia must have occurred and the delivering healthcare provider
probably applied excessive downward traction in the delivery of the anterior
shoulder. It was not until the mid to late 1990’s that research began to look
at this question and has now shown that in fact this belief was terribly
one of the largest studies ever published on brachial plexus injury, the
incidence of Erb’s palsy is approximately 0.15% of all deliveries (which is
about 1 in every 650 to 700 births). It is now a certainty that only about half
of these brachial plexus injuries come from a delivery complicated by shoulder
dystocia. The other half comes from deliveries in which NO shoulder dystocia occurred. This fact has now been demonstrated
in numerous studies that total more than 2600 Erb’s palsies (seen in the table
below). Shoulder dystocia, however, is definitely a risk factor when it comes
to brachial plexus injuries and this statistic will be further clarified under
the heading of “Risk Factors” seen below.
Author Erb’s with SD Erb’s without SD Total
Levine 1984 8 28 36
Gonik 1991 14 13 27
Jennett 1992 17 22 39
Nocon 1993 28 5 33
Lipscomb 1995 7 5 12
Perlow 1996 12 4 16
Sandmire 1996 19 17 36
Graham 1997 8 7 15
Peleg 1997 15 36
Brown 1997 17 13
Ecker 1997 43 37
Gherman 1998 23 17
Shivvers 1998 78 108
Gilbert 1999 860 751 1611
Raio 2003 58 36
Evans-Jones 2003 206 117 323
Totals 1413 (53.7%) 1216 (46.3%) 2629
conjunction with the large numbers seen in the table above, there are two other
compelling facts that verify the issue that most brachial plexus injuries are
not caused by the delivering healthcare provider. These are cesarean section
and the posterior arm at delivery. Before these facts can be discussed, the
origin of a brachial plexus injury / Erb’s palsy must be understood. These
injuries are caused by a stretching of the nerves in the neck region in the
area of C-5 to T-1 (cervical nerve roots 5, 6, 7, & 8 and thoracic nerve
root 1). These nerves will be further
discussed under “other facts” seen below.
However, to say it again, these injuries are caused by stretching of the
nerves beyond their capacity. Pulling on the baby’s head straight out does not
cause the injury (this would result in further shoulder impaction and possible
spinal cord injury for the baby). Erb’s palsy is a traction or vector injury.
The fact that numerous case reports exist of brachial plexus injuries
identified following cesarean section verifies that this stretching can occur
in utero. In fact, 60 of the 1611 Erb’s palsies (4%) seen in the Gilbert study
occurred in a cesarean section delivery.
Therefore, not all brachial plexus injuries occur in vaginal deliveries.
Furthermore, everyone would agree that human anatomy varies
from person to person. If we examine the population of the world, we will see
some individuals with very long necks and some with very short necks and
everything in between. Likewise, the birth canals of women also vary. The
distance from behind the pubic bone to the perineum (or just outside the birth
canal) is not the exact same distance for all pregnant women. Thus, one may
theorize that if a baby with a relatively short neck delivers vaginally in a
woman with a long distance from behind the pubic bone to the perineum, the
nerves in the neck region can be stretched beyond their capacity upon delivery
of the head before any healthcare provider applies any downward traction. In this
same mother-baby delivery scenario, the nerves in the neck may be stretched up
to their capacity upon delivery of the head but are stretched beyond their
capacity when the “normal” amount of downward traction is applied. Finally, in
the face of a shoulder dystocia, the nerves in the baby’s neck can be damaged
if excessive downward traction is applied. This is why excessive downward
traction (for the most part) should be avoided and other maneuvers utilized
when a shoulder dystocia is encountered (these maneuvers will be discussed
posterior arm is the second compelling finding that verifies that the
delivering healthcare provider does not cause most brachial plexus injuries.
Again, in the past it was presumed that all brachial plexus injuries occurred
because of excessive traction on the anterior shoulder in a delivery
complicated by a shoulder dystocia. Along with the fact that numerous studies
now show that approximately half of the injuries are seen in deliveries with no
shoulder dystocia, several recent studies have now identified that
approximately one-third of all Erb’s palsies are seen in the posterior arm of
the baby. One theory behind this occurrence is that during the labor process of
some pregnancies, the baby’s posterior shoulder becomes entrapped on the sacral
promontory. When the head delivers, the stretch (for the posterior shoulder) from
the sacral promontory to just outside the birth canal is tremendous and is much
further than the distance from behind the pubic bone to just outside the birth
canal (for the anterior shoulder). In addition, when a baby’s head delivers in
this situation, the gentle downward traction that is applied will, in essence, shorten
the distance between this entrapped posterior shoulder and would be beneficial
rather than harmful. The importance of this finding is that none of the
maneuvers applied by the delivering healthcare provider in managing a shoulder
dystocia will further stretch the nerves in a posterior arm injury. If
anything, they will shorten this distance. Thus, a brachial plexus injury of a
posterior arm occurs with the delivery of the head prior to any maneuvers
utilized by the healthcare provider. It should be mentioned that upward
traction on a baby’s head prior to the delivery of the anterior shoulder is not
a recognized obstetrical maneuver, will not result in the delivery of the
posterior shoulder before the anterior shoulder, and should not be used.
to summarize the four possibilities, the stretching of the nerves in a baby’s neck
can occur in utero prior to the onset of labor; can occur following the
delivery of the head before any downward traction is applied; can occur with
the normal amount of downward traction applied in normal deliveries; and can
occur with excessive traction in the face of a shoulder dystocia.
Risk Factors / Potential Warning Signs / &
studies have been published over the years that have looked at shoulder
dystocia and potential risk factors. However, from a simplistic point of view,
there are 2 basic risk factors for shoulder dystocia and these are a baby that
is too large for the mother’s birth canal (macrosomia, most commonly defined as
> 4000 to 4500 grams) or a mother’s pelvis that is too small or
poorly shaped for the birth of the baby (non-macrosomic baby) or a combination
of the two. A third potential risk factor is diabetes, which will be discussed
in more detail below. Numerous other “described” risk factors have been
studied, but none of them alone or in combination can accurately predict when a
shoulder dystocia will occur. In most studies, the ability to predict a
shoulder dystocia was well below 50%. Only a few have had a prediction rate of
greater than 50%, none were above 75%, and none have been re-producible. Therefore,
shoulder dystocia cannot be accurately predicted nor prevented (a statement
concurred by ACOG). This means that every healthcare provider who performs
vaginal deliveries will experience a shoulder dystocia and will need to know
how to handle the situation when it arises.
even though shoulder dystocia cannot be accurately predicted, warning signs and
other “described” risk factors need to be reviewed. It should be noted that many of the
“described” risk factors that have been associated with shoulder dystocia are
really risk factors for macrosomia and if macrosomia is not present, then these
are of no significance. Warning signs of an impending shoulder dystocia
primarily occur in a patient that is in labor. The only exception is a prior
history of a shoulder dystocia, especially one that occurred in a baby that was
non-macrosomic. This might imply that the primary factor lies with the size
and/or shape of the mother’s pelvis. For review, there are 4 primary shapes to
a mother’s pelvis. The most common shape is gynecoid, which is seen in
approximately 45% to 50% of women and is the most round in shape. The second
most common is the anthropoid pelvis, which is seen in about 30% of women and
is oval in an anteroposterior direction and could predispose to a persistent
occiput posterior (OP) position of the baby’s head in labor. The third most
common pelvis is the android pelvis, which occurs in about 20% of women and is
heart shaped. Finally, the platypelloid pelvis is the least common seen in only
3% of women and is oval from side to side (thus, the distance between the pubic
arch and sacrum is short). The platypelloid pelvis is the one that could
predispose to a shoulder dystocia, especially in the presence of a
are 2 possible warning signs that occur during labor. These are a prolonged
second stage and the need for instrumentation (use of a vacuum or forceps).
Unfortunately, neither of these alone or in combination can predict the
occurrence of a shoulder dystocia. In addition, no study to date has confirmed
that a prolonged second stage is actually a risk factor; however, it is often
associated with an instrumented vaginal delivery. Therefore, if either of these
or both exist, the best approach is to be prepared for a shoulder dystocia in
case one occurs (preparation for a shoulder dystocia is discussed below). As a
start, a few studies have suggested that induction of labor, the use of
epidural anesthesia, and the length of the first stage of labor might be risk factors
for a shoulder dystocia; however, the overwhelming data have shown that they
are not. Furthermore, the size and
position of the fetal shoulders is unlikely to affect whether or not the cervix
will dilate to complete (which involves the first stage of labor). The size and
shape of the fetal shoulders may, however, affect how well the baby traverses
the birth canal once the mother has dilated to complete (which is the second
stage of labor). Therefore, a prolonged second stage of labor is often listed as
something to be aware of.
As previously stated, a prolonged second stage of labor often
goes hand-in-hand with the potential need for the use of forceps or a vacuum to
accomplish the delivery. It is extremely important to remember that there needs
to be an indication for the use of forceps and/or vacuum. The indications for
the use of forceps or vacuum (and the definition of a prolonged second stage of
labor) are as follows:
indications such as cardiac disorders, severe pulmonary disorders, hemorrhage,
indications such as non-reassuring fetal heart tracings, etc. (or)
(3) prolonged second
stage – ACOG has defined the length of the second stage and if these times are
exceeded, then a diagnosis of a prolonged second stage can be entertained. For
nulliparous women – 2 hours without regional anesthesia, 3 hours with regional
anesthesia; For multiparous women – 1 hour without regional anesthesia, 2 hours
with regional anesthesia.
Maternal exhaustion is often listed
as an indication for an instrumented delivery, but this diagnosis cannot be
made in a short period of time once the patient becomes completely dilated.
Some attempt needs to be made in coaching and educating the patient regarding
how to create effective pushing, including a discussion on the potential need
for cesarean section (and the risks and complications of that procedure), if
she does not at least attempt some pushing effort. In addition, there are basic
requirements that need to be met when using forceps or a vacuum and these
requirements ARE THE SAME for both
instruments. They are a fully dilated cervix with an engaged fetal head at >
+2 cm station (which corresponds to a minimum of a low pelvic delivery).
Midpelvic deliveries are above + 2 cm station but the head is engaged (zero
station) and should only be done for a limited number of specific conditions
(too broad for this review article). High pelvic deliveries (negative station –
unengaged), for the most part, should not be done.
Many other “described” risk factors
have been evaluated over the years, including obesity, excessive maternal weight
gain (often defined as > 20 kilograms or 44 pounds), postterm (>
42 weeks gestation), large fundal height measurements, and a prior delivery of
a baby > 4000 grams. These, however, are primarily risk factors for
macrosomia. Again, if macrosomia is not present, then these do not increase the
risk for a shoulder dystocia.
regarding “risk factor” issues for shoulder dystocia, diabetes, especially
insulin dependent diabetes, produces two dilemmas. To begin with, diabetes can
increase the risk for macrosomia and macrosomia can increase the risk for
shoulder dystocia. In addition, diabetes, especially when poorly controlled,
probably increases the risk for shoulder dystocia in babies that are not
macrosomic because of its potential effect on the final dimensions of the baby
that delivers. The reason for this is easier to explain with an example. Let’s
say a given pregnancy was destined to have a baby of 3300 grams and 21 inches
in length. If this pregnancy were complicated by poorly controlled diabetes,
the baby may end up at 4000 grams but is still 21 inches in length, making the
dimensions of the baby “fatter” for its length increasing the chance for a
Turning our attention to brachial plexus injury, shoulder
dystocia is a risk factor. To show this, we need to review some statistics. To
begin with, there are approximately 4 million births in the United States every
year. It has now been demonstrated in over 15 studies that about 50% of the
Erb’s palsy cases occur in a shoulder dystocia delivery and the other 50% occur
in deliveries without a shoulder dystocia. If the incidence of Erb’s palsy is
approximately 1 in 650 to 700 births, then about 6000 cases of brachial plexus
injury will occur in a given year. If the overall incidence of shoulder
dystocia is 1%, then there are about 40,000 cases of shoulder dystocia per
year. Since approximately half of the Erb’s palsies that occur are seen in
deliveries with a shoulder dystocia, then 3000 brachial plexus injuries occur
in these 40,000 deliveries or about 1 in 13 deliveries (7.5%). The other 3000
cases occur in the 3,960,000 births in which a shoulder dystocia did not occur
or about 1 in 1320 deliveries (.075%). Thus, a brachial plexus injury is about
100 times more likely to be seen in a shoulder dystocia delivery, which is why
most healthcare clinicians had the belief that the disorder could only occur in
the presence of a shoulder dystocia.
However, when we only examine shoulder dystocia deliveries,
fortunately, the majority do not result in a permanent brachial plexus injury.
In fact, the risk of having any level of Erb’s palsy develop in a shoulder
dystocia delivery is approximately 15% (plus or minus 5%). Of these,
approximately 10% are permanent (plus or minus 5%).
Obstetrical Maneuvers That Can Be Utilized
maneuvers (that might be utilized once a shoulder dystocia is recognized) have
been reported and evaluated over the years. Categorically, there are 5 basic
groups, which are the McRoberts maneuver, suprapubic pressure, rotational
maneuvers, delivery of the posterior arm, and other maneuvers / heroic
procedures. One of the easiest and most often utilized maneuvers is McRoberts,
which was described in 1983 and involves hyper-flexing the legs back toward the
mother’s abdomen. An assistant may also apply suprapubic pressure as the
operator performs normal downward traction on the baby’s head. Suprapubic
pressure involves the application of downward pressure just cephalic to the
mother’s pubic bone (in the area of the mother’s bladder). This pressure is not
only downward, but also somewhat lateral in a direction toward the front of the
baby in order to adduct the baby’s shoulder to its chest (push the shoulder
toward the chest of the baby) and possibly achieve some rotation as well.
term “rotational maneuvers” is used in this manuscript because the words are
often intermixed and loosely applied by healthcare providers (i.e. Woods
maneuver, corkscrew maneuver, Woods screw maneuver, Rubin maneuver, etc.). As a
purist, in 1943, Woods described a maneuver of placing a hand on the chest side
of the posterior shoulder of the baby and trying to rotate the posterior
shoulder upward 180 degrees. This would cause the anterior shoulder to fall
below the pubic bone and conceptually, the baby would move in a corkscrew
pattern. In 1964, Rubin described placing a hand (on the back side of the baby)
behind either the anterior or posterior shoulder (which ever was the easiest to
access) and applying pressure to fold the shoulders toward the chest. In
essence, rotational maneuvers involve placing a hand on the baby’s shoulders
and applying pressure that rotates the position of the baby in the birth canal.
of the posterior arm involves the operator placing a hand into the vaginal
canal posteriorly up to a distance where the posterior arm of the baby is
identified. The arm is then grasped and swept across the baby’s chest and out
the birth canal, which will result in the anterior shoulder dropping below the
pubic bone allowing for delivery. This procedure, though very successful, can
often result in a fracture of the baby’s humerus.
maneuver often employed by midwifery is the Gaskin all-fours maneuver used in
patients without anesthesia (in most cases). The woman is asked to turn over
onto her hands and knees which may result in un-impaction of the anterior
shoulder and if not then gentle upward or downward traction might be applied.
Heroic maneuvers have also been described but should only be
utilized if the above 4 categories are not successful. In addition, some of
these maneuvers require extra training.
These include the deliberate fracture of the baby’s clavicle (which is
extremely difficult to do), cleidotomy (which is transecting the baby’s
clavicle with the use of scissors), symphysiotomy (which is transecting the
fibrous tissue between the pubic bones of the mother’s pelvis), abdominally
assisted vaginal delivery (where a hysterotomy is performed and the anterior
shoulder is pushed under the symphysis pubis from above), and the Zavanelli
maneuver, also called cephalic replacement (reported in 1985 and involves
placing the baby’s head back into the birth canal and performing a cesarean
section). The published reports on the Zavanelli maneuver have shown mixed
results ranging from normal outcomes to severe injuries and stillbirth.
the maneuvers, three other areas need to be discussed. The first is the use of
fundal pressure. This maneuver can be used PRIOR
TO the delivery of the baby’s head and as a purist; fundal pressure is
utilized in nearly every term cesarean section to effectuate the delivery.
However, fundal pressure should not be used once the head has delivered because
it will not help in delivering the shoulders, can further impact the anterior
shoulder against the mother’s pubic bone, and if applied while the operator
uses downward traction on the baby’s head could lead to injury. The second area
is the use of an episiotomy. An episiotomy will not result in the delivery of
the baby in the case of a shoulder dystocia because the baby is not impacted on
soft tissue. However, an episiotomy can allow more room for the operator’s hand
to perform rotational maneuvers or delivery of the posterior arm, if needed.
The third issue is the use of traction. Downward traction IS USED in the overwhelming majority of
deliveries. In fact, the definition of a shoulder dystocia is when the baby’s
shoulders do not deliver following the use of “normal downward traction”. Once the diagnosis is made, the maneuvers
above should be utilized. Excessive downward traction, however, can result in
injury to the baby’s brachial plexus and should be avoided unless all other
maneuvers fail and the decision is made to potentially sacrifice the arm in
order to prevent neonatal brain injury or death. Though very few studies exist
on this topic, it appears that neonatal brain injury can begin to occur if the
shoulder dystocia extends beyond 5 minutes in most cases (mean of 11 minutes
with a range of 3 to 20 minutes in one study). This area is not black and white
and also involves the status of the baby prior to the delivery of the head.
Again, upward traction on the baby’s head should not be performed prior to the
delivery of the anterior shoulder because it is not a recognized obstetrical
maneuver and will not result in the delivery of the posterior shoulder before
the anterior shoulder. (The Gaskin maneuver is excluded from this because the
patient is turning over onto all fours.)
Informed Consent and Scheduled Cesarean Section
could argue that informed consent and shoulder dystocia are words that should
not occur in the same sentence. The reason is because shoulder dystocia is
unpredictable. However, informed consent
can still play a role in this arena. Good labor management still involves an
attempt at estimating fetal weight. Though our ability to accurately estimate
fetal weight is often abysmal, we as healthcare providers should still make an
assessment and if we believe the fetal weight might be macrocosmic, options
should be given to the patient. These
include the options of a cesarean section and its associated risks versus the
risks of a vaginal delivery in the face of potential macrosomia. Also included
in this discussion is that our estimate may be off, and an unnecessary
procedure might occur. This estimated fetal weight can occur by either
ultrasound or physical examination (Leopold maneuvers). Studies have not really
shown one to be superior to the other. In fact, one study showed that a
multiparous mother’s prediction was closer than either an ultrasound or
If the healthcare provider believes that macrosomia might be
present, and the patient chooses to proceed with a vaginal delivery, it would
be prudent to have extra help present at the time of delivery. In addition,
though no studies exist on this issue, the use of forceps or a vacuum in this
setting may also not be warranted. If the patient is unable to push the baby
out, the safest approach might be to proceed with a cesarean section
(especially if the labor has a prolonged second stage).
the issue of a scheduled cesarean section for the purpose of preventing a
shoulder dystocia, ACOG has recommended that it be considered if the estimated
fetal weight exceeds 5,000 grams in non-diabetics or 4,500 grams in women with
diabetes. Again, these recommendations were made because of the high error rate
in accurately predicting macrosomia combined with the overall risks of permanent
injury with vaginal delivery in cases of macrosomia versus the risks of
concept that may be difficult for some healthcare providers to comprehend is
how brachial plexus injuries can occur without a shoulder dystocia or the use
of excessive traction. To begin with, numerous injuries and findings are seen
in normal spontaneous (non-instrumented) vaginal deliveries, both to the mother
and the neonate. Some of the reported injuries for the mother include
significant cervical and perineal tears, pelvic nerve injuries, a fractured
coccyx, and a separated symphysis pubis. For the neonate, there is significant
molding of the head, fractured skulls, subdural hematomas, fractured clavicles,
and brachial plexus injuries. All of these and more can occur because the power
of the uterine muscle is formidable. It should be noted that nearly all
healthcare providers who perform deliveries are not strong enough to replace an
inverted uterus without the aid of some uterine muscle relaxation medication.
This is because the force of the uterus (endogenous), especially when combined
with the force of the mother’s valsalva pushing efforts, will often exceed 100
pounds. This endogenous force is 4 to 9 times greater than the exogenous force utilized
in deliveries by the healthcare provider. The explanation of this point is very
technical and involves the use of physics and is presented in the next
paragraph for those who are interested.
measure the strength of uterine contractions by millimeters of mercury
(mmHg). A mmHg is a pressure measurement
that is roughly equal to 30 pounds of force per square meter of area. Using
intrauterine pressure catheter data, the force of a uterine contraction combined
with the mother’s expulsive forces often equals 80 mmHg, which equates to about
2,400 pounds of force per square meter of area. The cross-sectional area of the
birth canal when the cervix is completely dilated is about 80 square
centimeters. If the force of a labor contraction and pushing were equally
distributed throughout the uterus (meaning that the force upward against the
uterine wall in the fundus were equal to the force downward through the birth
canal), then the force in the birth canal when a mother is completely dilated
and is pushing would only be about 19 pounds. However, we know that a labor
contraction actually begins in the muscle fibers of the fundus and propagates
down the uterus toward the birth canal because its purpose is to push out what
is contained inside (i.e. the baby). Likewise, the direction of the
valsalva-pushing maneuver is also downward toward the birth canal. If the force
of a labor contraction with pushing were equally distributed in all directions
within the uterus, the baby would not move. Thus, the amount of force that is
directed downward through the birth canal is 6 to 8 times greater than the
force that would be pushing upward on the wall of the uterus in the fundus.
This equates to more than 100 pounds of force, which explains why injuries can
throughout this article we have used the words brachial plexus injury and Erb’s
palsy. The brachial plexus is a network of nerves that was briefly discussed at
the beginning and includes the nerves that are located in the neck from C-5 to
T-1. For clarification purposes, an
Erb’s palsy is defined as an injury to the nerve fibers of C-5 and C-6, and
mainly involves the mobility of the shoulder. A Klumpke’s palsy is defined as
injury to nerve fibers C-8 and T-1 and involves the mobility of the hand. The
C-7 nerve fibers primarily innervate the triceps muscle. Though these
explanations have been simplified and generalized, one should know that the C-5
through T-1 nerve fibers intermix with each other and the extent of immobility
will vary from injury to injury. For completion purposes, the C-4 nerve fibers
innervate the diaphragm and if this is damaged, the baby will often have
significant problems with respiration. Also, there are sympathetic nerve fibers
that come off the lower cervical / upper thoracic nerve roots and these fibers
return back up to innervate portions of the face and eyelid. If these nerves
are injured, Horner’s syndrome with a drooping eyelid might be seen.
conclusion, shoulder dystocia cannot be accurately predicted nor
prevented. Therefore, delivering
healthcare providers need to be prepared in handling these obstetrical
emergencies when they occur. Likewise, nothing can be done to prevent the
brachial plexus nerve injuries that occur in cesarean section births or deliveries
with no shoulder dystocia. Therefore,
protocols that involve shoulder dystocia deliveries will only have the
potential of impacting half of the brachial plexus cases that occur. Because
these injuries can occur in deliveries without a shoulder dystocia, if a baby
sustains a brachial plexus injury in a delivery complicated by shoulder
dystocia, this does not mean that excessive traction was utilized. With that said, being prepared for shoulder
dystocia is good medicine.
1. Perform an estimated fetal weight,
document this, and discuss options with the patient if there is a belief that
macrosomia might exist (i.e. cesarean section option if > 4500 grams in a
diabetic patient or > 5000 grams in a non-diabetic patient).
2. Observe the length of the second stage
of labor and do not hesitate to ask for more help at the time of delivery,
especially if the decision is made to use forceps or a vacuum.
3. If forceps or vacuum are utilized, have
a recognizable indication and be sure that all of the requirements are met
(completely dilated, engaged head at > +2 cm station in most
4. If a vaginal delivery attempt is made
on a patient with diabetes (especially one with insulin dependence that is
poorly controlled), again do not hesitate to ask for more help at the time of
delivery (regardless of the estimated fetal weight).
5. When a shoulder dystocia is encountered
– call for help – both obstetrical and pediatric.
6. Remember the maneuvers:
hyper-flexing the legs back toward the mother’s abdomen; Apply suprapubic
pressure; downward and somewhat lateral toward the face direction or the front
of the baby
maneuvers – Rubin’s or Wood’s
Delivery of the
7. Avoid fundal pressure once the baby’s
head delivers. An episiotomy may give more room for rotational maneuvers and /
or delivery of the posterior arm.
8. Write a note of the maneuvers utilized
and the position of the baby’s head at the time it delivered – remember these
notes are for future healthcare providers to understand what occurred at the
References or Suggested Reading:
1. Shoulder dystocia. ACOG Practice Bulletin; Number 178, May 2017.
2. Fetal macrosomia. ACOG Practice Bulletin; Number 173, November
3. Operative vaginal delivery. ACOG Practice Bulletin; Number 154, November 2015.
4. Grobman WA, Miller D, Burke C, et al.
Outcomes associated with introduction of a shoulder dystocia protocol. Am J
Obstet Gynecol 2011;205:513-7.
5. Hoffman MK, Bailit JL, Bramnch DW, et
al. A comparison of obstetric maneuvers for the acute management of shoulder
dystocia. Consortium on Safe Labor. Obstet Gynecol 2011;117:1272-8.
6. Evans-Jones G, Kay SPJ, Weindling AM,
et al. Congenital brachial palsy: incidence, causes, and outcome in the United
Kingdom and Republic of Ireland. Arch Dis Child Neonatal Ed 2003;88:F185-F189.
7. Raio L, Ghezzi F, DiNaro E, et al.
Perinatal outcome of fetuses with a birth weight greater than 4500 g: an
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Dr. Quilligan is currently Editor Emeritus of the American Journal of Obstetrics & Gynecology. He was the Co-Chair of the National Institute of Child Health and Human Development (NICHHD) Research Planning Workshop on “Electronic Fetal Heart Rate Monitoring” regarding research guidelines and interpretation that was held in 1997. The terminology developed at this workshop has now been adopted by ACOG and AWHONN.
In Dr. Quilligan’s distinguished career, he has authored numerous peer review articles, has edited and authored several major textbooks in the field of obstetrics, and has given lectures on a wide variety of topics nationwide. He is also the past Chairman of the Departments of Obstetrics & Gynecology at Yale University, University of Southern California, University of California at Davis, and University of California at Irvine. Dr. Quilligan reports no conflicts of interest.