I am a UCer. I think this is a fantastic thread, and very helpful. Thanks to all those that left comments, as many are helpful. I don't see anything that indicates fear in any of the comments. What I see is a question asked, and answered to the best of the commentors abilities. Just because someone points out that the signs of distress are very subtle, and can be missed even by the most observant mama, doesn't make them full of fear. UC, to me, is about following your intuition and making the most informed choices possible. Knowing what can happen, and how severe it could be, is an important part of being informed.
Back to the OP-
I have two close friends that had babes with respiratory issues, one due to mec. One had a HB, and when her water broke and there was a good amount of mec, so the MW transferred her. She had a nice, all natural birth with her HB MW there, but the baby needed immediate resuscitation due to the mec. babe was intubated and went to the NICU for 2 weeks before being well enough to go home. It was good that she transferred, as the babe needed the help to stay alive. This is a good example of knowing when something is wrong and taking action, averting a crisis.
The other friend had a happy, normal, HB, and afterwards the MW checked over the babe, who looked and acted just fine, said all was well, and left. Several more hours later, mama fell asleep with her new babe sleeping near by. Her DH checked on them, and saw the sweet new babe was not breathing. 911 was called, they went to hospital, but she could not be revived. In retrospect, there were a several subtle signs that no one had noticed, not even the MW. This mama had 6 kids already, 5 were born at home, so it's not like she was inexperienced or her intuition was bad. The MW was not well trained, and failed to spot the subtle signs, and the mom- well, she was merely human. Tired after labor, and trusting all was well, she rested. AFAIK this was not due to mec, but is a good example of how things can be missed, by even the most dedicated mama.
I also know a few with light staining, and all the babes were fine. I don't know the details, but none required NICU.
It's wise to know what issues are a sign of impending crisis, and have an idea of what you will do if they happen. Everyone has a different idea of what UC is to them, but I personally like to know these things. My UC plan includes transfer for certain things, and that includes heavy mec. I accept that there are problems that I cannot fix, and want to be able to access help it's needed.