Table 1 Summary of demographic characteristics and outcomes

Age at Mustard palliation (years)

2.2 (0.6-6)

Age at delivery (years)

31 (25-37)

Age at CMR (years)

32 (27-37)

Gravidity

n (%)

Gravida 1

5 (31%)

Gravida 2

3 (19%)

Gravida ≥ 3

8 (50%)

Cardiac anatomy

Transposition of the great arteries with intact septum

14 (82%)

Transposition of the great arteries with ventricular septal defect

2 (12%)

Transposition of the great arteries with aortic coarctation

1 (6%)

Cardiovascular events in pregnancy

Decline in NYHA classification

1 (6%)

Sustained tachyarrhythmia resulting in heart failure

1 (6%)

Cardiac arrest

1 (6%)

Obstetric events

Premature rupture of membranes

1 (6%)

Placental abruption

1 (6%)

Fetal/neonetal events*

Premature delivery < 37 weeks

3 (18%)

Admission to intensive care unit

4 (24%)

Death

1 (6%)

*events not mutually exclusive