Case 85: Delivery

 CASE 85: DELIVERY

History

You are urgently called to the delivery room of a 26-year-old woman to help deliver the baby.

The mother is 41 weeks into her second pregnancy, having had a normal term delivery of a

3.97 kg female infant 2 years ago.

Nuchal and anomaly scans were normal and antenatal care was unremarkable. The baby was

moving normally prior to labour.

When she arrived on labour ward contracting, the symphysiofundal height was noted to be

41 cm.

At first assessment the cervix was 3 cm dilated and she was advised to continue mobilizing.

Spontaneous rupture of membranes occurred and she was examined again after 4 h and

the cervix was still 3 cm. A syntocinon infusion was commenced to augment labour and an

epidural sited, with cardiotocograph monitoring also commenced. After 4 h, the cervix was

7 cm and then 10 cm after a further 4 h. The woman was encouraged to start active pushing

and 35 min later the head had crowned in a direct occipitoanterior position.

The midwife noticed that the head did not extend normally on the perineum and that the

chin appeared to be wedged against the perineum. She had attempted delivery of the shoulders with the next two contractions but this had not been achieved.

Questions

• What is the diagnosis?

• How would you manage this scenario?100 Cases in Obstetrics and Gynaecology

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ANSWER 85

This condition, where the fetal shoulders and trunk fail to deliver after the head, is shoulder dystocia. Complications include perinatal mortality, hypoxic encephalopathy, brachial

plexus injury (e.g. Erb’s palsy), as well as maternal postpartum haemorrhage and third- or

fourth-degree tear.

Shoulder dystocia occurs in 1 in 200 deliveries and is associated with various risk factors

(though in many cases it cannot be predicted). In this case the woman had a relatively large

previous baby, this baby had persistently been large on examination, she is post dates and

progress was a little slow.

! Risk factors for shoulder dystocia

• Estimated fetal weight (>4.5 kg)

• Previous big baby (>4 kg)

• Previous shoulder dystocia

• Slow progress in the first and/or second stage of labour

• Post dates delivery

Management

This is an obstetric emergency and the emergency bell should be activated with help summoned from the senior midwife, other available midwives, anaesthetist and paediatrician, as

well as the most senior obstetrician available.

A series of manoeuvres are practiced by labour ward staff at ‘skills and drills’ sessions in

preparation for such an event. The first four points should be carried out in that order. If the

shoulders do not then deliver, then points 5–7 can be attempted in any order, depending on

the operator’s experience.

1. Call for help.

2. Consider episiotomy: this will not allow the shoulders to deliver but will allow

manipulation of the baby to achieve delivery.

3. Elevate the legs (McRoberts manoeuvre): the procedure involves flexing the maternal hips, thus positioning the thighs up onto the abdomen. This simulates the squatting position, with the advantage of increasing the inlet diameter. The head of the

bed should be placed flat.

4. Suprapubic pressure: external manual suprapubic pressure is applied to the fetus’s

anterior shoulder, in such a way that the shoulder will adduct or collapse anteriorly

and encourage the baby’s shoulder to pass under the symphysis pubis. Pressure is at

first constant, and then in a rocking fashion if the baby remains undelivered.

5. The operator’s fingers should enter the pelvis: the index and middle fingers should be

inserted past the fetal head and behind the anterior shoulder, then pressure exerted

on the back of that shoulder to attempt to rotate the baby (Rubin’s manoeuvre). This

can also be tried with the posterior shoulder from the front of the fetus, rotating the

shoulder toward the symphysis in the same direction as with the Rubin II manoeuvre (Wood screw manoeuvre).

6. Removal of the posterior arm: the clinician must insert his or her hand far into the

vagina and locate the posterior arm. Once the arm is located, the elbow should be

flexed so that the forearm may be delivered in a sweeping motion over the anterior

chest wall of the fetus.Case 85: Delivery

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7. Roll onto all-fours position: If the above manoeuvres fail, the woman should be rolled

onto the all-fours position which increases the true obstetrical conjugate (shortest

pelvic diameter through which the fetal head must pass during birth) by as much as

10 mm and the sagittal measurement of the pelvic outlet by up to 20 mm.

Delivery usually occurs by stage 5. If it fails then last resort measures are the procedure

of replacing the fetal head into the pelvis and performing emergency caesarean section or

performing symphysiotomy (if caesarean delivery is not an option) to enlarge the pelvic

diameters.

KEY POINTS

• Shoulder dystocia is an obstetric emergency and requires immediate action.

• All health professionals delivering babies must be well rehearsed with the appropriate manoeuvres.