Shoulder Dystocia

SHOULDER DYSTOCIA (Sh.D) An Evidence Based Approach Dr.Mohamed El Sherbiny MD Obstetrics&Gynecology Senior Consultant Damietta General Hospital Damietta Egypt

SHOULDER DYSTOCIA Evidence Based Sources:

•PubMed •Cochrean library • ACOG Issues Guidelines • National Guideline Clearinghouse

:Definition Shoulder dystocia (Sh. D) is the inability to deliver the fetal shoulders after delivery of the head, without the aid of specific maneuvers (ie. other than gentle downward traction on the head) . Spong et al. 1995; Beal et al 1998 ; Bruner 1998

Definition Objective definition :

Mean head-to-body delivery time > 60 seconds Spong et al. 1995; Beal et al 1998 ; Bruner 1998

As operative vaginal delivery of malposition and malpreresntation has declined, Sh.D has emerged as one of the more important clinical and medico-legal complications of vaginal delivery Baskett, 2001

Shoulder dystocia will still the obstetric nightmare

PATHOPHYSIOLOGY Shoulder dystocia results from a size discrepancy between the fetal shoulders and the pelvic inlet when: 2. The bisacromial diameter is large relative to the biparietal diameter 3. Pelvic prim is flat rather than gynecoid .

Types of Shoulder Dystocia 1- High Shoulder Dystocia 2-Low Shoulder Dystocia

High -1 Shoulder Dystocia • Both shoulders fail to engage (Bilateral Sh.D). (Rare) • More common with mid -pelvic assisted delivery • This presentation often requires a cephalic replacement. (The most

difficult)

Low-2 Shoulder Dystocia • Failure of engagement of the anterior shoulder (Unilateral Sh.D). ,The commonest:

Usually easily dealt with by Standard techniques

Incidence Varies according to: 2. Criteria for diagnosis. 3. Prophylactic manoeuvre done Subjective: 0.6-1.6% Objective: Much lower ACOG Bulletin,22, Novamber2000

Release techniques

Complications of Sh D

1.Maternal 2.Fetal

Maternal Complications (25%) • Postpartum hemorrhage

11%

• Vaginal laceration

19%

• Perineal tears 2nd&3rd

4%

• Cervical laceration

2%

The largest study (285 cases) Gherman et al Am J Obstet Gynecol176:656, 1997

techniques FetalRelease Complications of Sh D

Fetal Complications of Sh D Injuries are a common outcome associated with shoulder dystocia and may occur despite use of proper standard obstetric manoeuvers ACOG practice 1997 (B: II-2)

Fetal Complications of Sh D Brachial plexus injuries, Fractures of the humerus, and Fractures of the clavicle are the most commonly reported injuries associated with shoulder dystocia ACOG practice 1997 (A: II-2)

Fetal Complications of Sh D

Traction combined with fundal pressure has been associated with a high rate of brachial plexus injuries and fractures ACOG practice 1997 (B: II-2)

Fetal Complications of Sh D

Fewer than 10% of deliveries complicated by shoulder dystocia will result in a persistent brachial plexus injury. ACOG practice 1997(A: II-2)

Fetal Complications Release techniques Head –shoulder interval > 7min.

Brain injury (sensitivity & specificity :70 %) • With hypoxic fetus it is much shorter Quzounian et al Am J Obstet Gynecol 178;S76,1998

Can shoulder dystocia be predicted ?

RISK FACTORS FOR SHOULDER DYSTOCIA

PRECONCEPTIONAL: 

Maternal birth weight

 Prior shoulder dystocia 12%      

Prior macrosomia Pre-existing diabetes Obesity Multiparity Prior gestational diabetes Advanced maternal age O'Leary &, Leonetti; 1990

RISK FACTORS FOR SHOULDER DYSTOCIA

Antenatal: •

Excessive maternal weight gain

• Macrosomia • G. diabetes •

Short stature

•

Post term O'Leary &, Leonetti; 1990

RISK FACTORS FOR SHOULDER DYSTOCIA

Intrapartum: 2. Protracted or arrested active phase 3. Protracted or failure of descent of head 4. Need for midpelvic assisted delivery Hopwood,1982 ; Baskett &,Allen, 1995

RISK FACTORS FOR SHOULDER DYSTOCIA Most of the prenatal and antenatal risk factor are interrelated with fetal macrosomia. So the main risk factor is:

Fetal Macrosomia

Macrosomia Although macrosomia is clearly the main risk ,factor 50-60 % of Shoulder Dystocia are of < 4 Kg !! Acker et al, Obst. Gynecol 66:762, 1985 Baskett &Allen Obstet Gynecol 86:14, 1995

Prediction Most cases of shoulder dystocia cannot be predicted because accurate methods for identifying which fetuses will experience ACOG Practice 1997 (B: II-2).

Macrosomia Fetal body configuration may be more important than macrosomia per se Greater shoulder /head circumference:

• Infant of diabetic mother • Post term (21% at 42 weeks)

Macrosomia And Shoulder Dystocia Wight (Kg) vacuum . forceps

Non

Diabetic

Diabetic+

or

4 : 4.25

5.2%

8.4%

12.2%

4.25: 4.5

9.1%

12.3%

16.7%

4.5 : 4.75

14.3% 19.9%

27.3%

4.75: 5

21.1% 23.5%

34.8%

Nesbitt et al, Am J Obstet Gynecol 179;476, 1998

Unfortunately • The diagnosis of fetal macrosomia is imprecise. • For suspected fetal macrosomia, the accuracy of estimated fetal weight using ultrasound biometry is no better than that obtained with clinical palpation (Leopold's manoeuver). ACOG Issues Guidelines on Fetal Macrosomia 2000(Level :A) 2000

Can shoulder dystocia be Prevented ?

Macrosomia There are 2 controversial prophylactic measures 1-Prophylactic labor induction 2-Elective CS

Induction of Labor Suspected fetal macrosomia is not an indication for induction of labor, because induction does not improve maternal or fetal outcomes. ACOG Issues Guidelines on Fetal Macrosomia 2000(Level B): .

Induction of Labor Labor induction for suspected fetal macrosomia results in an increased CS delivery rate without improving perinatal outcomes. Sanchez-Ramos Obstet Gynecol Systemic Review . November 2002:100:997-1002

Induction For Gestational Diabetes There is very little evidence to support either elective delivery or expectant management at term. A single randomized controlled trial suggest that induction of labor in GDM treated with insulin reduces the risk of macrosomia. Boulvain et al:Cochrane Review,2001. In: The Cochrane Library, Issue 2 2003. Oxford: Update Software.

Prevention of Sh. D. :.c.s Planned cesarean delivery on the basis of suspected macrosomia in the general population is not a reasonable strategy because the number and cost of additional cesarean deliveries required to prevent one permanent injury is excessive ACOG 1997 (B: II-2).

Furthermore 3% of brachial plexus injury are associated with C.S.

When is CS recommended in

?

macrosomia

ACOG Issues Guidelines on Fetal Macrosomia 2000 Prophylactic CS may be considered for suspected fetal macrosomia with estimated fetal weights of: g in non diabetic women 5,000 < g in diabetic women 4,500 < (Level :C)

.

ACOG Issues Guidelines on Fetal Macrosomia 2000 With an estimated fetal weight more than 4,500 g, with : • A prolonged second stage of labor or • Arrest of descent in the second stage It is an indication for CS delivery. Level B

.

MANAGEMENT (Within5- 7 minutes) .

Management 1-Suprapubic pressure 2-McRobert manoeuver 3- Woods corkscrew . 4-Rubens manoeuver 5-Delivery of P. shoulder 6-Zavanelli 7-All fours 8-Cleidotomy 9-symphysiotomy

ACOG Issues Guidelines Recommendation 1991

1-Call for help: assistants, anesthesiologist 2-Initial gentle attempt of traction. 3-Generous episiotomy. 4-Suprapubic pressure.

ACOG Issues Guidelines Recommendation 1991

5-The Mc Roberts manoeuvre (Exaggerated hyper flexion of the thighs upon the abdomen.) & Suprapubic pressure in the direction of the Foetal face

.

McRoberts manoeuvre: X ray pelvimetry study

No increase in pelvic dimensions. Decrease in the angle of pelvic inclination P=0.001 Straightening of the sacrum P= 0.04% Tends to free the impacted anterior shoulder

Gherman et al Obstet Gynecol 95:43 ,2000

Mc Roberts manoeuvre IU pressure by 97% (P<0.0001) U. contraction amplitude by 25% (P<0. 001) Applied additional 31 Newtons pushing force

Buhimschi et al Lancet 358:470 ,2001

ACOG Issues Guidelines Recommendation 1991

If Mc Roberts failed: 6-Woods manoeuvre: •The hand is placed behind the posterior shoulder of the fetus. •The shoulder is rotated progressively 180 d in a corkscrew manner so that the impacted anterior shoulder is released. .

ACOG Issues Guidelines Recommendation 1991

7-Delivery of the posterior arm : .

By inserting a hand into the posterior vagina and ventrally rotating the arm at the shoulder

delivery over the perineum

ACOG Issues Guidelines Recommendation 1991

8-Other techniques include:

• Intentional fracture of the clavicles or the humerus Or

• Zavanelli Maneuver. .

The Zavanelli Manoeuver

Reversing the mechanism of delivery of the vertex under tocolytic

1. The head first manually rotated to the occipito anterior (Pre-restitution) position

2.Flexion of the head, Returning it to the vagina with upward constant firm pressure, followed by CS

Zavanelli maneuver The Zavanelli Manoeuver • It would usually only be applicable in those rare cases of bilateral Sh.D. • It involves an emergency procedure that is not without risks of its own . • It has minimal applicability as it needs

Immediate CS

Zavanelli maneuver The Zavanelli Manoeuver In an analysis of 92 cases of shoulder dystocia managed by Zavanelli Maneuver: • Success rate : 92 % • Stillbirth: 7% • Neonatal death : 9%. • Brain damage : 11%

Maternal complication: Rupture uterus ,vaginal rupture ,severe infection,

Sanberg; Obstet Gynecol.;93:312. 1999

All- Fours Manoeuver It consists of placing the patient onto her hands and knees

All- Four Manoeuver • It allows rotational movement of the sacroiliac joints resulting in a l-cm to 2cm increase in the sagittal diameter of the pelvic outlet. • It disimpact the shoulders, and allowing it to slide over the sacral promontory. •Effective also for bilateral Sh.D.

All- Fours Manoeuver In an analysis of 82 cases of shoulder dystocia managed by all-four manoeuver : • Success rate : 83% • Maternal complications 1.2% •Neonatal complications : 4.9%, •Time for complete delivery : 2 to 3 Ms. Drummond et al. J Reprod Med. ;43:439; 1998.

ACOGRelease Issues Guidelines techniques 1997

There is no evidence that any one maneuver is superior to another in releasing an impacted shoulder or reducing the chance of injury. .(B: II-2)

ACOGRelease Issues Guidelines techniques 1997

However, the Mc Roberts maneuver is easily facilitated and has a high success rate without an associated increased risk of injury to the newborn .(B: II-2)

Bilateral Shoulder Impactions All- Fours Manoeuver: Used at all circumstances except if the patient has received epidural analgesia, heavy analgesia or anesthesia

Zavanelli Manoeuver: Used if the patient has received epidural analgesia or heavy analgesia with obstetric facilities for emergency CS

Prophylactic Procedures

When shoulder dystocia is anticipated , prophylactic McRobert position is recommended

Shoulder Dystocia Drill Shoulder dystocia drill should be as important as CPR for the mother and neonate. This should be taught and practiced regularly, by all staff involved with delivery

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