PTMC Delivers Dramatic Cardiac Relief and Maternal Safety in Severe Mitral Stenosis During Pregnancy: Study

What are your options when a pregnant patient with severe mitral stenosis continues to deteriorate despite optimal medical management? Rheumatic heart disease remains a leading contributor to maternal morbidity in Asia, and the stakes are highest when mitral stenosis progresses during pregnancy. A new study in BMC Pregnancy and Childbirth sheds light on how percutaneous transvenous mitral commissurotomy (PTMC) delivers outcomes that matter—both for mothers and babies.

PTMC During Pregnancy: Study Design and Population

Researchers conducted a retrospective observational study at a tertiary center in Thailand, enrolling 18 pregnant women with rheumatic mitral stenosis who underwent PTMC between 2002 and 2022. Most women were in the second trimester at intervention, and all had symptomatic disease unresponsive to standard therapy. Eligible patients had a mitral valve area ≤1.0 cm² or high transmitral gradients, plus favorable valve morphology.

Procedural Success and Hemodynamic Improvements

PTMC was technically successful in 94% of cases. The procedure increased the mitral valve area from 0.98 cm² to 1.5 cm² and halved the mean transmitral gradient and left atrial pressure. Systolic pulmonary artery pressure also decreased significantly. Importantly, the vast majority of women improved from NYHA class III–IV to class I–II after the intervention.

Safety, Radiation Exposure, and Maternal Outcomes

Radiation safety is always a concern for fetal health. In this cohort, median fluoroscopy time was just 3.76 minutes and median air Kerma was 21 mGy—well within safe limits. No procedure-related deaths, strokes, or cardiac tamponade occurred. Among 12 women with follow-up data, all survived to delivery, and none required repeat intervention or mitral valve surgery.

Neonatal Outcomes and Delivery

Neonatal outcomes were generally reassuring. No neonatal deaths or congenital anomalies were observed. Average birth weight was 2.48 kg, with a quarter of infants classified as low birth weight. Preterm birth and intrauterine growth restriction rates were within expected ranges for this high-risk group.

Why These Findings Matter

PTMC offers a vital, less invasive alternative to surgery for pregnant patients with severe mitral stenosis, providing rapid symptomatic relief and meaningful hemodynamic improvements. This Southeast Asian data, while small, supports the use of PTMC as a safe and effective option when medical therapy fails.

Conclusion

For obstetricians and cardiologists managing high-risk pregnancies complicated by rheumatic mitral stenosis, PTMC delivers substantial clinical benefits with minimal maternal or fetal risk when performed by experienced teams. Ongoing prospective studies are needed, but current evidence suggests PTMC should be strongly considered in symptomatic patients refractory to medication.

Key Points

PTMC achieved a 94% procedural success rate and significant hemodynamic improvement in pregnant women with severe mitral stenosis.

All patients improved to NYHA class I or II after the procedure.

No maternal or neonatal deaths, and no congenital anomalies were observed among available follow-up cases.

Procedure used low radiation doses, with careful shielding and minimized fluoroscopy.

PTMC represents an effective, less invasive alternative to surgery for eligible pregnant patients unresponsive to medical therapy.

Citation: Sricholwattana S, Kosum P, Theerasuwipakorn N, Srimahachota S. Percutaneous transvenous mitral commissurotomy during pregnancy: a contemporary Southeast Asian experience. BMC Pregnancy and Childbirth. 2026;[in press]. https://doi.org/10.1186/s12884-026-09824-5