ShoulderDystocia ( ACOG Medical Student Education Module 2011)
Definition Difficulty in delivery of fetal shoulders Failure to deliver fetal shoulder without utilizing facilitating maneuvers Prolonged head-to-body delivery time >60 seconds Incidence: 0.2-3% of all live births; represents an obstetric emergency
Bilateral ShoulderDystocia The posterior shoulder is not in the hollow of the pelvis. This presentation often requires a cephalic replacement.
Unilateral ShoulderDystocia Unilateral shoulder dystocia is usually easily dealt with by standard techniques.
Pathophysiology Size discrepancy between fetal shoulders and maternal pelvic inlet Macrosomia Large chest:BPD Absence of truncal rotation Fetal shoulders remain A-P or descent simultaneously
D - Diabetes O- Obesity P- Post term pregnancy, prior large baby E- Excessive weight gain during pregnancy No evidence based data: Male Short maternal stature Abnormal pelvic shape/size
Unpredictable 25-50% have no defined risk factor! 50% of cases occur in infants whose birth weight is <4000g TURTLE SIGN: represented by the retraction of the fetal head after expulsion, may herald shoulder dystocia, shoulder dystocia is not diagnosed until the usual attempts at the delivery of the head fail.
Complications Maternal Hemorrhage 4th degree laceration Fetal Fx of humerus or clavicle Brachial plexus injury (Erb’s/Klumpke’s palsy) Asphyxia/cord compression Physician Litigation: 11% of all obstetrical suits
Management Goal: Safe delivery before neontal asphyxia and/or cortical injury 7 minutes!!! Episiotomy Suprapubic Pressure McRoberts Maneuver Woods or Rubin Maneuvers Zavenelli Push back the delivered fetal head into birth canal and perform an emergent c/s
HELPERR Algorithm H: Call for Help; Shoulder dystocia is called if shoulders cannot be delivered with gentle traction E: Evaluate for Episiotomy: Not routinely indicated; maybe needed when attempting intra-vaginal maneuver L: Legs (McRoberts): Hyperflexion and abduction of hips—initial maneuver
P (Suprapubic Pressure): No fundal pressure; combination of McRoberts and suprapubic pressure resolves most shoulder dystocias Enter (Internal Maneuvers): oblique diameter rotational maneuvers Woods screw (1943): Insert two fingers into posterior vagina and apply pressure to the anterior aspect (clavicular) of the posterior shoulder and abduct and rotate that shoulder, the posterior shoulder could be rotated 180° degrees to the anterior, and this would disimpact the obstructed anterior shoulder. The subsequent addition of gentle downward traction with a contraction would then result in delivery. Rubin(1964): either the anterior or posterior shoulder, which ever was more accessible, be adducted and brought toward the fetal chest. Insert two fingers on the posterior aspect (scapular) of the anterior or posterior shoulder and also rotate the baby 180° to reduce the obstruction. Remove: Delivery posterior arm Roll the patient: Gaskin maneuver or all four positions
McRoberts Maneuver 42% success rate + Suprapubic pressure = 54-58% Brings pelvic inlet and outlet into more vertical alignment Flattens sacrum Cephalad rotation of pubic symphysis Elevates anterior shoulder and flexes fetal spine Increases IUP by 97% Increases amplitude of contractions +31N of pushing force
Preliminary Measures: Gentle pressure on the fetal vertex in a dorsal direction will move the posterior fetal shoulder deeper into the maternal pelvic hollow, usually resulting in easy delivery of the anterior shoulder. Excession angulation (>45 degrees) is to be avoided. (Gabbe, et al., Obstetrics: Normal and Problem Pregnancies, Churchill Livingstone, New York, 1986)
Suprapubic Pressure Moderate suprapubic pressure is often the only additional maneuver necessary to disimpact the anterior fetal shoulder. Stronger pressure can only be exerted by an assistant. (Gabbe, et al., 1986)
Oblique DiameterRotational Maneuver Delivery may be facilitated by counterclockwise rotation of the anterior shoulder to the more favorable oblique pelvic diameter, or clockwise rotation of the posterior shoulder. During these maneuvers, expulsive efforts should be stopped and the head is never grasped !!
Delivery of thePosterior Arm To bring the fetal wrist within reach, exert pressure with the index finger at the antecubital junction. (E. Sandberg. American Journal of Obstetrics and Gynecology, 1985; 152: 481.)
Delivery of thePosterior Arm Sweep the fetal forearm down over the front of the chest.
Delivery of thePosterior Arm If less invasive maneuvers fail to affect this impaction, delivery should be facilitated by manipulative delivery of the posterior arm by inserting a hand into the posterior vagina and ventrally rotating the arm at the shoulder with delivery over the perineum.
All- FoursManoeuverIt consists of placing the patient onto her hands and knees
The Chavis Maneuver Described in 1979. A “shoulder horn” consisting of a concave blade with a narrow handle is slipped between the symphysis and the impacted anterior shoulder. This used like a shoe-horn as a lever where the symphysis is the fulcrum.
The Hibbard Maneuver Release of the anerior shoulder is initiated by firm pressure against the infants jaw and neck in a posterior and upward direction. An assistant is poised, ready to apply fundal pressure after proper suprapublic pressure As the anterior shoulder slips free, fundal pressure is applied, and pressure against the neck is shifted slightly toward the rectum. Proper suprapubic pressure is continued.
The Hibbard Maneuver Continued fundal and suprapublic pressure results in an upward- inward rotation of the newly freed anterior shoulder and a further descent in a position beneath the pubic symphysis.
The Hibbard Maneuver As a result of the previous maneuvers, the transverse diameter of the shoulders is reduced. Lateral (upward) flexion of the head releases the posterior shoulder into the hollow of the sacrum.
Fracture of theClavicle The anterior clavicle is pressed against the ramis of the pubis. Care should be taken to avoid puncturing the lung by angling the fracture anteriorly. Theoretically, a fracture of the clavicle is less serious than a brachial nerve injury and often heals rapidly.
The ZavanelliManeuver First described in 1988 Consists of cephalic replacement and then cesarean delivery. Mixed reviews in the literature.
Summary Cannot accurately predict BE PREPARED! Consider risk factors Be prepared to perform various maneuvers Diagnose and treat quickly Obtain assistance from nursing staff and NICU
ProphylacticCesarean? Not recommended by ACOG Exceptions: Consider if… >5000g in mother without DM >4500g in mother with DM
Shoulder dystocia is well suited for simulation training. The obstetric birth simulator NOELLE (Gammard Scientific, FL, USA) is one such model.