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 deliv- ery 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 mobiliz- ing. 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.
· What is the diagnosis?
· How would you manage this scenario?
This condition, where the fetal shoulders and trunk fail to deliver after the head, is shoul- der 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.
This is an obstetric emergency and the emergency bell should be activated with help sum- moned 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. These are incorporated into the mnemonic HELPERR, which is taken from the Advanced Life Support in Obstetrics (ALSO®) programme. The programme and its copyright are owned by the American Academy of Family Physicians (www.aafp.org/also).
· Call for Help.
· Consider Episiotomy: this will not allow the shoulders to deliver but will allow manip- ulation of the baby to achieve delivery.
· 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.
· Suprapubic Pressure: external manual suprapubic pressure is applied to the fetus’ 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 for 60 s, and then in a rocking fashion for a further 60 s.
· 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 shoul- der toward the symphysis in the same direction as with the Rubin II manoeuvre (Wood screw manoeuvre).
· 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.
· 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 conjucate by as much as 10 mm and the sagittal measurement of the pelvic outlet 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.