Reproductive · Year 2 · from Reproductive
Case 1: Shoulder Dystocia
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Source: Wikipedia - Shoulder dystocia - CC BY-SA 4.0
Case Presentation
A 34-year-old G2P1 woman at 40 weeks gestation presents in active labor. Her first pregnancy resulted in a vaginal delivery of a 3.9 kg infant complicated by a prolonged second stage. She has gestational diabetes controlled with diet. Current estimated fetal weight by ultrasound is 4.2 kg. Labor progresses normally and she reaches complete cervical dilation. After 90 minutes of pushing, the fetal head delivers but then retracts against the perineum (the "turtle sign"). The anterior shoulder fails to deliver with routine maneuvers. Shoulder dystocia is recognized immediately. The McRoberts maneuver is performed (hyperflexion of maternal thighs against the abdomen), and suprapubic pressure is applied by an assistant. The anterior shoulder does not deliver. The provider performs the Woods corkscrew maneuver (rotating the posterior shoulder anteriorly). The infant is finally delivered with delivery of the posterior arm. Total head-to-body delivery time is 75 seconds. The infant weighs 4.4 kg and has initial left arm flaccidity with absent Moro reflex on the left. Apgar scores are 6 at 1 minute and 8 at 5 minutes. Pediatric evaluation reveals Erb's palsy (C5-C6 brachial plexus injury) presenting with the characteristic "waiter's tip" posture. Physical therapy is initiated. At 3 months of age, the infant shows significant recovery of arm function.
Key Learning Points
- Shoulder dystocia occurs when the fetal anterior shoulder impacts the maternal pubic symphysis after delivery of the head; risk factors include macrosomia, gestational diabetes, prior shoulder dystocia, and prolonged second stage
- The "turtle sign" (retraction of the delivered fetal head against the perineum) is the classic indicator of shoulder dystocia
- McRoberts maneuver (hyperflexion of maternal thighs) with suprapubic pressure is the first-line intervention; additional maneuvers include Woods corkscrew and delivery of the posterior arm
- Erb's palsy (C5-C6 injury causing "waiter's tip" posture) is a potential complication; most cases recover spontaneously within the first year