Shoulder dystocia dr Ahmed Walid Anwar Morad

Benha Faculty of Medicine

1. Shoulder Dystocia DR/ Ahmed Walid Anwar Morad Professor of OB/GYN Faculty of Medicine Benha University 2021

2. Definition Incidence Causes Risk factors Classification Recognition Management Complication Prevention

3. Definitions Subjective : a vaginal cephalic delivery that requires additional obstetric manoeuvres to deliver the fetus after the head has delivered and gentle traction has failed. (RCOG2012) Objective : Prolonged head to body delivery time > 60 sec ( Spong et al,1995)

4. Incidence: Wide variation 0.6 – 1.4% (ACOG 2002 ) 0.58% and0.70 % (RCOG2012) >10% if one uses the head-to-body delivery interval Incidence increased with increased fetal body weight Incidence of SD FBW 1% < 4 kg 5% 4- 4.5 kg 10% < 4.5kg

5. Causes of SD → ?? Disproportion between: The biacromial diameter of the fetus (12-15cm) & The antero -posterior diameter of the pelvic inlet. (Large sized baby through average sized pelvis\ average sized baby through small sized pelvis )

6. Cardinal movement of labour Head is floating • Engagement • Descent • Flexion • Internal rotation Crowning • Extension (delivers head) • External rotation ( restitution ) • Expulsion: (Delivery of anterior and posterior Shoulders)

7. Risk Factors for S. dystocia (RCOG 2012) Intra-partum Fetal Antepartum Prolonged 1 st stage Macrosomia > 4.5kg D : D M 2ndry arrest O : O besity (BMI> 30kg/m²) Prolonged 2 nd stage P : P revious SD Oxytocin augmentation I : I nduction of labor Assisted vaginal delivery RF are absent in > 50% of cases (Langer et al,1991) S. dystocia cannot be predicted from clinical characteristics or labor abnormalities (Basket,2000)

8. Classification of shoulder dystocia Affected shoulders Laterality Severity Commonly: Anterior shoulder impacted behind the symphysis pubis. Less commonly: Posterior shoulder impacted on the sacral promontory. Unilateral Mild Both the posterior & the anterior shoulders do not cross the pelvic brim Bilateral Sever

9. Recognition of S. dystocia Shoulder dystocia should be suspected when the underlying signs are present : Crowning: Slow crowning of fetal head Extension : Difficulty with delivery of the face and chin The fetal head retracts into the perineum (turtle sign) after expulsion due to reverse traction from shoulders being impacted at the pelvic inlet . External rotation (restitution): Failure

10. Recognition of S. dystocia Diagnosis is made when : Expulsion : Gentle downward traction of the fetal head fails to complete delivery of the anterior shoulder.

11. Management of S. dystocia Dos “HELPERR” mnemonic Avoid 4Ps H — Call for help. P unic E — Evaluate for episiotomy. P ulling L — Legs ( McRobert’s maneuver). P ushing P — Suprapubic pressure. P ivoting E — Enter maneuvers (internal rotation). R — Remove the post arm. R — Roll the patient (all-fours positions). R — Last Resort maneuvers Quick Systematic Approach

12. Emergency manoeuvres for shoulder dystocia do one of three things: Increase the functional size of the bony pelvis Decrease the bisacromial diameter of the fetus Rotating the fetus into the wider oblique diameter Each manoeuvre is allowed for up to 30 seconds before moving to the next one.

13. Additional manoeuvres for S. dystocia Last Resort 2 nd line 1 st line Cleidotomy Zavanelli maneuver. Abdominal rescue Symphysiotomy Posterior axilla sling traction Internal rotation manoeuvre Rubin’s II Manoeuvre Wood’s screw Manoeuvre Reverse Wood’s screw Manoeuvre McRobert’s manoeuvre Delivery of posterior arm Suprapubic pressure (Rubin 1) Rotation of the woman onto all fours

14. Internal Rotation Maneuvers Rubin’s II Manoeuvre Wood’s screw Manoeuvre Reverse Wood’s screw Manoeuvre Aim of these manoeuvres is to effect 1) internal rotation of the shoulders into the more favorable oblique inlet diameter or 2) delivery of the posterior arm to reduce the bisacromial diameter.

15. Rubin’s II Maneuver Woods Corkscrew Maneuver

16. Remove the Posterior Arm ( Jacquemier’s Maneuver) : the obstetrician must insert his hand far into the vagina and attempt to locate the posterior arm. Once forearm is located, the elbow is flexed so that arm can be delivered by a sweeping motion over the chest wall of the fetus . Disadvantage : difficult, fetal trauma, unsuccessful if fetus is so tightly lodged in the pelvis

17. All-fours M.: Position: The woman is placed on her hands & knees. Action: Gravity pushes the posterior shoulder anteriorly. The flexibility of the sacro -iliac joints increases the saggital D of the pelvic inlet. The posterior shoulder is delivered first . Success : 83%

18. “Last Resort” Maneuvers Indications : failure of maneuvers described in the “HELPERR” mnemonic Includes: Cleidotomy Zavanelli maneuver Abdominal rescue Symphysiotomy Posterior axilla sling traction.

19. Prevention of shoulder dystocia 1) Suspected macrosomic fetus without maternal diabetes : N o evidence that early induction of labour (IOL) prevents shoulder dystocia. Elective caesarean section is not recommended . Estimation of fetal weight is unreliable and the majority of macrosomic infants do not experience shoulder dystocia. An additional 2345 caesarean sections would need to be performed to avoid one permanent injury from shoulder dystocia.

20. Prevention of shoulder dystocia 2) Suspected macrosomic fetus with maternal diabetes : Induction of labour at term can reduce the incidence of shoulder dystocia Elective caesarean section should be considered if the estimated fetal weight is greater than 4.5 kg.

21. Prevention of shoulder dystocia 3) In women who have had a previous shoulder dystocia : When discussing mode of delivery in these women, we should consider : T he severity of any previous neonatal or maternal injury, T he size of the fetus & Maternal choice

22. Take Home Message SD is unpredictable and largely unpreventable obstetrician nightmare . Staff should be alert for evidence of shoulder dystocia and well trained for its management. Management should be quick and systematic with great care to avoid maternal complications and neonatal permanent Hypoxic damage. The McRoberts manoeuvre with or without suprapubic pressure will resolve the majority of cases. In 2 nd line maneuvers, no maneuver is superior to other but its use depends on obstetrician experience and patient circumstances. Post-delivery maternal examination, neonatologist review, labor event documentation and parent consultation are essential.