Bentzion,
If your wife had a miscarriage already and your Rav/Rebbe told you to not fly, then what are you doing here in the CR asking if anybody had any issues. Emunas chochomim should be enough. Stay home or travel only to where you can get to by train or car. It’s that simple. Some women are more sensitive and cannot handle climbing a lot of stairs in early pregnancy, even though millions of pregnant women do without issues. Should you try to force that woman to climb stairs? I don’t think you should. In the merit of being careful, you should be zocheh to have doros yesharim, sweet, beautiful children, and you and your wife shouldn’t know any more tza’ar of precious lost neshomos.