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: (A) Heart Failure, (B) Thromboembolism, (C) Hemorrhage, (D) Arrhythmia
Answer is D. Adverse cardio vascular events due to congenital heart disease in pregnancy

Arrhythmia (most common)
Heart failure
Thrombo embolism.