This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Gynaecology & Obstetrics
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 
Select and explain. 
A. Heart Failure, B. Thromboembolism, C. Hemorrhage, D. Arrhythmia
D: Arrhythmia
Answer: D: Arrhythmia 
Explanation: Adverse cardio vascular events due to congenital heart disease in pregnancy

Arrhythmia (most common)
Heart failure
Thrombo embolism.