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

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9 Cardiac disease
A young pregnant woman who had had a repair for a congenital heart condition had the midwifery
aspects of her care provided by specialist teenage midwives. She was under paediatric cardiac follow
up every two years and due for transfer to adult congenital heart disease services. She had moderate
to severe pulmonary regurgitation and right ventricular dilation, but was well and asymptomatic. She
collapsed and died suddenly in mid-pregnancy. An inadequate autopsy failed to ascertain the precise
cause of her death although a specialist cardiac pathologist considered it to be most probably due to
a cardiac arrhythmia. There are no details regarding her health in pregnancy.
There are some key lessons to be drawn from this case about the management of women with congenital
heart disease. Firstly, because of her signifi cant heart disease, her care should have been arranged under
a specialist high-risk obstetric team 1 . As she was a teenager the team could still have put her in touch
with her local teenage pregnancy midwife. Secondly, although the importance of seamless transfer from
paediatric to adult congenital heart disease services is vital, so too is timely advice regarding pregnancy
and contraception 1 . One of the consensus views from the RCOG Study Group on heart disease and
pregnancy states : 2
“A proactive approach to preconception counselling should be started in adolescence and this
should include advice on safe and effective contraception. Proper advice should be given at the
appropriate age and not delayed until transfer to the adult cardiological services”.
This is the second consecutive triennium in which a death, probably arrhythmic related to right ventricular
failure, has been reported in women with a surgically repaired tetralogy of Fallot, traditionally believed to
be one of the less risky conditions with regard to pregnancy. However it is important to note that it is the
commonest form of cyanotic heart disease, which occurs once in every 3,600 live births, and that even in
historical series, survival rates into the fi fth decade are similar to that of the general population 3 . Surgically
repaired tetralogy of Fallot is probably the commonest condition seen in adult congenital heart disease
clinics, thus its repeated appearance as a cause of maternal cardiac death may simply be a refl ection
of the numbers of these women now becoming pregnant. However, the fact that some may die means
there is no room for complacency and those caring for these women in pregnancy should be aware that
assessment of right ventricular function is vital. A recent study of pregnancy outcomes in women with
congenital heart disease confi rms that the presence of impaired sub-pulmonary ventricular systolic function
and/or severe pulmonary regurgitation increases the risk of an adverse outcome4.
Three women died from pulmonary hypertension, one less than reported in the last triennium. One mother,
who had Eisenmenger’s syndrome secondary to a ventricular septal defect (VSD), and who had been
advised about the risks of becoming pregnant and continuing with her pregnancy had excellent antenatal
care managed by a multidisciplinary team in a tertiary centre. Despite this she collapsed and died shortly
after an elective caesarean section. The other two women died between one and four weeks after delivery;
both had undiagnosed primary pulmonary hypertension with no symptoms antenatally, and these deaths,
too, were probably unavoidable.
Another woman, whose death is counted in Chapter 10, died from pulmonary hypertension secondary to
recurrent pulmonary emboli from antithrombin defi ciency secondary to chronic liver disease.
It is encouraging that maternal deaths from pulmonary hypertension seem to be falling and this may refl ect
better pre-pregnancy counselling and acceptance of contraception, or, alternatively, improved care.
Incidence of pulmonary vascular disease
Over the nine month period between March and November 2006, the United Kingdom Obstetric
Surveillance System (UKOSS) reported six confi rmed cases of pulmonary vascular disease. This gives