This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Obstetrics, Subject name: Gynaecology & Obstetrics
A pregnant woman with severe mitral stenosis is likely to undergo failure in the anetnatal period. Best method to prevent cardiac failure in this patient is? 
Select and explain. 
A. T. Furosemide through out pregnancy, B. Balloon mitral valvuloplasty in second trimester, C. Digoxin for all hea patients, D. Admit all at 30 weeks
B: Balloon mitral valvuloplasty in second trimester
Answer: B: Balloon mitral valvuloplasty in second trimester 
Explanation: Balloon mitral valvuloplasty is the best treatment to prevent failure in severe MS. The ideal time for surgery would have been the interpregnancy interval, but since the patient is already pregnant, 20 - 24 weeks is the most preferable time. However in cases of severe mitral stenosis, surgery may be performed any time during pregnancy in the interest of the mother. Other treatment includes diuretics, b blockers and limited physical activity