Shoulder dystocia is a rare obstetric emergency that immediately
places the mother and the fetus at risk for significant morbidity
and mortality. It is diagnosed when, after delivery of the fetal head,
further expulsion of the fetus is prevented by impaction of the
fetal shoulders within the maternal pelvis.1Shoulder dystocia is considered an emergent
situation that the clinician must recognize and quickly respond
to by properly delivering the fetus.
The incidence of shoulder dystocia varies from less than 1 to
4 percent of cephalic spontaneous vaginal deliveries.2–7 Differing
definitions of shoulder dystocia may account for some of this variability.
Some reports require that maneuvers for shoulder release be documented
on the chart whereas others accept the physician’s clinical
diagnosis of shoulder dystocia. Other definitions look at the timing
of the delivery of the head, the delivery of the shoulders, or the
completion of the birth. The rare occurrences of shoulder dystocia
make design of prospective studies difficult, both in describing
the incidence and in evaluating the efficacy of various release
Shoulder dystocia may not be anticipated in advance. Many risk
factors are associated with shoulder dystocia. However, many patients
with shoulder dystocia have none of these risk factors. Emergency
Physicians usually do not have knowledge of the patient’s
prenatal history, ultrasound reports, or previous deliveries. This
makes it difficult to predict shoulder dystocia. It is imperative for
the Emergency Physician to be knowledgeable and comfortable with
release maneuvers in the event they encounter shoulder dystocia
during a precipitous delivery.
Shoulder dystocia is usually diagnosed when, after delivery of
the fetal head, the fetal shoulders fail to deliver despite standard
gentle traction on the fetal head. It results from impingement of
the biacromial diameter of the fetus against the maternal pubic
symphysis anteriorly and the maternal sacral promontory posteriorly.9
Shoulder dystocia is a rare and potentially catastrophic obstetrical
emergency. The clinician must deliver the
fetus quickly and without applying excessive forces that may result in
fetal injury. Always be prepared for the possibility of shoulder
dystocia. Recognize the possible associated risk factors that include
fetal macrosomia, maternal diabetes, a prior history of shoulder
dystocia or macrosomia, prolonged second stage of labor, post-term
pregnancy, multiparity, obesity, and operative vaginal delivery
from the midpelvis.9
Fetal macrosomia is defined as fetal growth beyond a specific
weight, usually 4000 to 4500 gm, regardless of the fetal gestational
age. The risk of shoulder dystocia is 9.2 to 24 percent in nondiabetic
pregnant women, and 19.9 to 50 percent in diabetic women when birth
weight is greater than 4500 grams.10 The ability to predict
fetal macrosomia is limited. Shoulder dystocia can occur unexpectedly
in infants of normal birth weights.10 A simple algorithm
to help determine if shoulder dystocia or fetal macrosomia may be
present is shown in Figure 112-1.
Log In to View More
If you don't have a subscription, please view our individual subscription options below to find out how you can gain access to this content.
Want remote access to your institution's subscription?
Sign in to your MyAccess profile while you are actively authenticated on this site via your institution (you will be able to verify this by looking at the top right corner of the screen - if you see your institution's name, you are authenticated). Once logged in to your MyAccess profile, you will be able to access your institution's subscription for 90 days from any location. You must be logged in while authenticated at least once every 90 days to maintain this remote access.
If your institution subscribes to this resource, and you don't have a MyAccess profile, please contact your library's reference desk for information on how to gain access to this resource from off-campus.
AccessEmergency Medicine Full Site: One-Year Subscription
Connect to the full suite of AccessEmergency Medicine content and resources including advanced 8th edition chapters of Tintinalli’s, high-quality procedural videos and images, interactive board review, an integrated drug database, and more.
Pay Per View: Timed Access to all of AccessEmergency Medicine
24 Hour Subscription $34.95
48 Hour Subscription $54.95
Pop-up div Successfully Displayed
This div only appears when the trigger link is hovered over.
Otherwise it is hidden from view.