Shoulder dystocia Flashcards
(30 cards)
Shoulder dystocia definition
A vaginal cephalic delivery that required additional obstetric manoeuvres to deliver the fetus after the head is delivered and gentle traction has failed
(RCOG 2012)
How does shoulder dystocia occur?
Either the anterior, or less commonly the posterior, fetal shoulder impacts on the maternal symphysis, or sacral promontory respectively
(RCOG 2012)
What diameter are the fetal shoulders in a shoulder dystocia?
In normal labour, the fetal shoulders enter the pelvic brim in the oblique or transverse diameter. In shoulder dystocia there is an arrest of the normal mechanism of labour as the shoulders attempt to enter the pelvis in the anteroposterior diameter of the pelvic brim
(Mayes 2012)
Incidence of shoulder dystocia
There is a wide variation in the reported incidence of shoulder dystcoia. Ranges from 0.1% to 3.0%
Prompt (2017)
Incidence of brachial plexus injury
2.3-16% of shoulder dystocia’s
RCOG 2012
What percentage of shoulder dystocia’s occur with infants who weigh less than 4000g?
48%, therefore over half of shoulder dystocia’s occur in babies over 4000g
(RCOG 2012)
Risk factors associated with shoulder dystocia
Previous shoulder dystocia Macrosomia >4.5kg Diabetes Maternal BMI >30 IOL Prolonged first stage Secondary arrest Prolonged second stage Oxytocin augmentation Assisted vaginal delivery (RCOG 2012)
Reducing risk of shoulder dystocia for those with risk factors
Horvath et al (2012) did a meta analysis supporting IOL to reduce to risk of shoulder dystocia in maternal diabetes and suspected macrosomia.
The montgomery ruling (2015) is where a baby was brain damaged following shoulder dystocia. Pay out won despite being managed correctly as she wasn’t offered an IOL despite large baby identified and having gestational diabetes.
Risk to mum
`PPH Third and fourth degree tears Uterine rupture Psychological distress (Prompt 2017)
Risk baby
Stillbirth Hypoxia Brachial plexus injury Fractures (humeral and clavicular (Prompt 2017)
Signs of shoulder dystocia
- Difficulty with the delivery of the face and chin
- The head remaining tightly applied to the vulva or even retracting (turtle neck sign)
- Failure of restitution of the fetal head
- Failure of the shoulders to descend
(RCOG 2012)
Time limits for the management of shoulder dystocia
No conclusive data but appears to be a very low rate of hypoxia ischemic injury upto five minutes
CESDI reported that 47% of babies died within 5 minutes of the head being delivered; but a high proportion already had a pathological CTG
(RCOG 2012)
What rate does the fetal Ph drop?
0.04 a minute. Within 7 minutes the pH will have decreased by 0.28
How to manage a shoulder dystocia?
- CALL FOR HELP IMMEDIATELY
- Lay flat and stop maternal pushing
- Clearly state when people come into the room - ‘this is a shoulder dystocia’
- McRoberts
- Suprapubic pressure
- Consider episiotomy if will make internal manoeuvres easier, but not always necessary
- Internal manoeuvres - deliver posterior arm + internal rotational manoeuvres
- All fours or repeat the above again
(RCOG 2012)
Why discourage maternal pushing?
May exacerbate impaction of shoulder
RCOG 2012
McRoberts’ Position
The first choice of manoeuvre as has proven to be safe and effective. Requires the mother to lie flat on her back, then she is assisted into an exaggerated knee position. Once the mother has adopted this position, the midwife should be able to proceed with a normal delivery of the shoulders
(Mayes 2012)
How does McRoberts’ position work?
Straighten the lumbosacral angle, roatate the maternal pelvis towards the mother’s head and increases the relative anterior posterior diameter of the pelvis. If in lithotomy position, need to be removed from her supports
(RCOG 2012)
Success rate of McRoberts’ manoeuvre
As high a 90%, with a low rate of complications and is non invasive (RCOG 2012)
Who to call for help in an obstetric?
- Senior Midwife
- Additional maternity staff
- Experienced obstetrician
- Neonatal team
(Prompt 2017)
Suprapubic pressure
Used if McRoberts’ if unsuccessful. Has a 50% success rate. (RCOG 2012)
Is intended to adduct and then displace the anterior shoulder away from the symphysis pubis and so allow it to enter the pelvis in the oblique diameter. Pressure is applied using the hand against the baby’s back in the direction that the baby is facing. (Mayes 2012)
Only routine traction should be applied to the fetal head when assessing whether the manoeuvre has been successful (RCOG 2012)
Suprapubic pressure - rocking or continuous pressure?
No clear difference in the efficacy
RCOG 2012
Traction applied during shoulder dystocia
The same degree of traction is applied as during normal birth, and in an axial direction
(Prompt 2017)
Episiotomy???
Shoulder dystocia is a bony dystocia and as such is not greatly affected by soft tissue. An episiotomy may prevent injury to the mother’s pelvic floor and perineum during any direct manipulation of the fetus and/or accommodate the midwife’s or obstetrician’s hand whilst undertaking internal manoeuvres
(Mayes 2012)
Internal manoeuvres
Should be used if McRoberts’ or suprapubic pressure fails. When gaining access to the vagina for internal manoeuvres enter into the sacral hollow (posteriorly) as that is the most spacious part of the pelvis. The whole hand should be entered posteriorly to perform internal rotation or delivery of the posterior arm. The women should be brought to the end of the bed to make access to the vagina easier
