Due to the lack of evidence-base, guidelines on
pregnancy management are based on expert
consensus (Oakley et al, 2003). One of the larger
studies (albeit retrospective) of pregnant women
with heart disease in 2001 analysed 599 pregnancies
in 562 women with pre-existing cardiac
disease (mostly adult congenital heart disease) and
developed a risk-scoring system to predict the risk
of an adverse maternal event (pulmonary oedema,
sustained arrhythmia, stroke, cardiac arrest, or
cardiac death), based on a points system. One
point is awarded for each criteria: