Saving Mothers' Lives: - Public Health Agency for Northern Ireland

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5 Amniotic fl uid embolism
Sub-standard care
Care was judged to be sub-standard in seven (36%) cases. Even though many of these deaths would
probably have been inevitable, the defi ning feature of most of them was a delay in instituting resuscitation
although there were other contributory features, as discussed later. In three cases there was a failure to
recognise the severity of the acutely ill women and in two further cases resuscitation was delayed because
women were sent for unnecessary diagnostic scans. For two other women more resuscitation was delayed
because either the relevant drugs and equipment were not readily to hand or the cardiac arrest team were
unable to gain access to the labour ward.
Care for these women could also be judged sub-standard for other reasons. One woman who collapsed
just after delivery had had a seven to eight hour second stage before eventual delivery. For three women
who were delivered by emergency caesarean section there was a delay in delivery, in one case for
more than fi ve hours. The Managing Obstetric Emergencies and Trauma (MOET) course recommends
caesarean section delivery of the infant within fi ve minutes of cardiac arrest to facilitate resuscitation 3 .
One woman’s care was compromised by having to be transferred from an isolated maternity unit in a
haemodynamically unstable condition and in a further case the mother was left unattended in labour for
half an hour after being given pethidine and then found collapsed. One woman, who due to her beliefs
refused to accept blood transfusion, had no advanced care plan regarding the management of any
obstetric emergency.
Pathology
At post mortem the initial features of AFE are of congested, relatively airless lungs with petechial
haemorrhages on mesothelial, particularly pleural surfaces. Often other organ systems are normal and the
diagnosis can only be confi rmed on histology. Fetal squames can often be identifi ed within the maternal
lung capillaries on routine H&E staining and amniotic fl uid mucins and lanugo hairs may also be present.
Sometimes the material may be so scanty, as with three cases this triennium, that immunochemistry is
required for identifi cation.
In this triennium an autopsy was performed for all but one of the women. In one case the report was not
available to the assessors and histology was not performed, or not available, in another. The one woman
who did not have an autopsy collapsed a few minutes after delivery. This woman was a Late death, dying
two months later, and the diagnosis in her case was made clinically. In three other cases AFE was not
confi rmed and the diagnosis was also made clinically and, for a further three, the diagnosis was diffi cult
and only confi rmed by immunocytochemistry. In the remaining cases fetal squames were either so obvious
on routine staining that no special stains were required or were confi rmed by immunochemistry.
The incidence of amniotic fl uid embolism
A prospective, national study of amniotic fl uid embolism is currently being undertaken by UKOSS 4 . Over
the fi rst eighteen months of the study from February 2005 to July 2006, 19 confi rmed cases of amniotic
fl uid embolism were reported in an estimated 1,080,000 total births. This gives an estimated incidence in
the UK of 1.8 cases per 100,000 maternities with a 95% confi dence interval from 1.1 to 2.8.
Acknowledgements
This Chapter has been seen and commented on by Derek Tuffnell FRCOG.