I can weigh in on this point. I'm in a little different position because I didn't know I had any issues with my heart before pregnancy, and also based on the type of damage my mitral stenosis was most likely acquired (rheumatic heart disease from a strep infection) and a bit degenerative over time. Here is the timeline:
--Most likely age 5-15: rheumatic fever undetected or remembered by either my or my parents as anything unusual.
--Age 27 - first pregnancy, full term no symptoms
--Age 30 - second pregnancy, full term no symptoms
--Age 32 - third pregnancy, developed persistent dry cough (that was especially bad lying down) and some shortness of breath in last month or so of full-term pregnancy. No heart diagnosis, symptoms went away after delivery
--Age 34 - fourth pregnancy, twins. During late 2nd trimester developed heart failure symptoms, e.g. shortness of breath, severe dry cough especially when lying down (had to sleep in a chair), severe fatigue, and finally coughing up splats of blood the size of a quarter. That last symptom got me sent from urgent care to the hospital for an echo, admitted to the cardiac floor with severe mitral stenosis. Got one treatment to help mature the babies' lungs. Then got placental abruption and bleeding. Transported to a different hospital with a NICU and perinatologist where they delivered the twins via C-section in a dodgy 50/50 chance of survival procedure wherein both I and one of the twins coded but were brought back. 5 days in ICU for me. 4 months in hospital for the twins as they were born as 27 weeks. First two years sucked as they had many medical problems, had to quit my job AND hire a nanny and still barely made it through. They are fine now with minimal problems.
My heart failure symptoms improved somewhat after the delivery. After I recovered from the C-section I got a valvuloplasty (balloon) to open the stenotic valve. This reduced the stenosis to moderate and also gave me moderate regurgitation (my cardiologist said regurgitation usually increases by one notch, mine was more like 2 notches). This has been reasonably stable for 21 years now, sometimes edging into mod-severe ranges depending on the test. Still no symptoms anything like what I had while pregnant and severe.
I didn't get to make a choice like you are doing. I have no way of knowing what degree of stenosis I had for my first three pregnancies. We also have zero intention of having more kids. But here is how I would think about it.
If you take the meds, I think the question is how much risk of disability, what disabilities, how much risk of prematurity and how early (every week counts). I'd want to know if I have to take them the whole time or if they can be started if heart failure starts happening. Do you have any symptoms now?
If you skip medications and go into heart failure they will need to deliver early, so you could be talking about fetal non-viability, a NICU stay or disabilities for your child, and danger to you. But maybe you could squeak by? I always wonder if the symptoms I had at the end of pregnancy #3 were early-stage heart failure from a more moderate stenosis. That was unpleasant but not life-threatening.
If you get treated first -- I'm a little surprised they're not recommending this a bit more, but let me think it through. If the balloon works, you'll still have your native valve but it will hopefully be working better to support the pregnancy, though you and your doctor might still need to manage some enhanced stroke risk (I take 325mg aspirin). If you get a tissue replacement, you might have a well-functioning valve to be pregnant with, but you are awfully young for tissue and would need multiple re-dos so I don't think that's a great option. If you get a mechanical replacement, you're hopefully set for life but you'd need to manage anti-coagulation very carefully during pregnancy. That might carry some of the same risks to you or your baby that the "medication route" does? I know it can be done but it might not be the preferred choice. Finally, I'm wondering if they think you really aren't "ready" for mitral valve replacement or repair as your stenosis is only moderate. That's also why I'm wondering if you are symptomatic or have been in the past, are already taking meds for it, etc. The increased blood flow needed to support pregnancy (especially the twins I had) seems to worsen the symptoms.
Kinda rambly but I hope this gives you some ideas to ponder and questions to ask. A lot might depend on your access to medical care (big urban area with NICU, etc. or more rural). Happy to answer anything else from my experience.
