A 30-year-old woman with rheumatic mitral stenosis (MVA 1.0 cm²) presents with NYHA Class III dyspnoea during pregnancy (28 weeks). Echo shows mitral valve score (Wilkins) of 6/16, no significant MR, no left atrial thrombus. What is the intervention of choice?

• A Percutaneous mitral balloon valvotomy (PMBV/Inoue technique) — safe in pregnancy, fluoroscopy minimised with echo guidance ✓
• B Emergency Caesarean section followed by mitral valve replacement
• C Open mitral commissurotomy via cardiopulmonary bypass — preferred over catheter-based in pregnancy
• D Medical management with digoxin and diuretics alone until delivery

Explanation

Percutaneous mitral balloon valvotomy (PMBV) is the intervention of choice for symptomatic severe mitral stenosis during pregnancy when: Wilkins score ≤ 8 (favourable valve morphology), no significant MR, no LA thrombus. Pregnancy increases cardiac output by 30-50% and these haemodynamic changes can precipitate decompensation in critical MS. PMBV can be performed with minimal fluoroscopy (using echo guidance) after 20 weeks to reduce fetal radiation exposure. Cardiopulmonary bypass carries 20-30% fetal mortality and is reserved for failure of PMBV or unsuitable anatomy. Medical therapy alone is inadequate for NYHA III symptoms with critical MS.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.