20 year old married woman with history of congenital heart disease comes for pre-conceptional counselling. Which of the following is most likely adverse event that she might face in pregnancy
Adverse cardio vascular events due to congenital heart disease in pregnancy

Arrhythmia (most common)
Heart failure
Thrombo embolism.
Heart Failure
Thromboembolism
Hemorrhage
Arrhythmia