Table 2 Proposed risk stratification model for pregnant women with Fontan circulation. Women allocated to ‘intermediate’ or ‘very high risk’ groups based on achieving ≥1 criteria for that group

NYHA class

I

II

III-IV

SaO₂ (%)

≥ 94%

90–93%

< 90%

MVO₂ (ml/kg/min)

>60%

50–60%

<50%

Systemic ventricular function impairment

none

mild

moderate/severe

AVVR

none/mild

moderate

severe

Fontan related complications^a

none

none

at least one^a

Failing Fontan^b

no

no

yes