Definition, Incidence and Complications impaction of anterior shoulder of fetus against symphysis pubis after fetal head has been deliv...
- Definition, Incidence and Complications impaction of anterior shoulder of fetus against symphysis pubis after fetal head has been delivered (life threatening emergency)
- occurs when breadth of shoulders is greater than biparietal diameter of the head
- incidence is 0.15-1.4% of deliveries
- watch for ”turtle sign” (head advances during contraction but returns to previous position at end of contraction)
- chest compression by vagina or cord compression by pelvis can lead to hypoxia
- danger of brachial plexus injury (Erb palsy)
- fetal fracture (clavicle, humerus, cervical spine)
- maternal perineal injury, may result in PPH
Associated Conditions maternal
- maternal
- obesity
- diabetes
- multiparity
- fetal
- prolonged gestation
- macrosomia
- labour
- prolonged 1st and 2nd stages
- prolonged deceleration phase (8-10 cm)
- instrumental midpelvic delivery
Management
- goal: to displace anterior shoulder from behind symphysis pubis
- initial gentle traction with maternal pushing
- adequate analgesia
- apply suprapubic pressure (to dislodge shoulder) with downward traction
- ask for help
- legs into hyperflexion on maternal abdomen (McRobert maneuver)
- anterior shoulder disimpaction
- release posterior shoulder (deliver posterior arm and shoulder)
- maneuver of WoodÃs corkscrew (insert hand beyond occiput into vagina and push anterior shoulder forward to the oblique or push the posterior shoulder through a 180 degree arc to reduce the biacromial diameter presented to the pelvic inlet)
- episiotomy (midline)
- cleidotomy: deliberate fracture of the clavicle (last resort)
- Zavanelli maneuver (involves flexion of the fetal head,replacement of the fetus within the uterine cavity and emergent ,C-section; reported success in a small series)
