I’m not sure that the cerebral angiography is usually done with sedation or general anaesthetic. I think it is more usually done with a local anaesthetic at the insertion point only. I would describe mine as uncomfortable but nothing to be frightened of. Honestly.
The contrast material question is a good one. In an adult, it is like having a hangover after a night of excessive alcohol: the material presumably gets a bit stuck into the smaller vessels and takes a while to be absorbed / flushed through, so it feels like having a hangover. I would discuss the risks to your child from that element of the procedure with the neurosurgeon / interventional radiographer. It will also depend on how much contrast material they end up using: depending on how complex an AVM you have might lead to very few surveys of the arteries required or may mean that they want to look at quite a number of flows, so that would reduce or increase any risks.
The other thing to bear in mind is that if you don’t do something about your AVM, it might be that it could kill you or do you significant damage during your pregnancy, so you do need to think about your own health to make sure you are going to be able to look after your family. Knowing how big or complex an AVM you have may be vital information during your pregnancy.
In terms of the X rays, I would have thought it would have been closely focused on your head, so less likely to affect baby.
You’re definitely in a less usual position and it is good to ask these sort of questions of the doctor.
Everything is about balancing the risks. The risks of leaving it, the risks of looking at it and there may not be a perfect balance. You’ll need to decide, supported by your doctors, what the right balance is in your situation.
The other thing I can think of is whether a CT scan without contrast would show the docs what they need to see, or whether that would have fewer or more risks to baby. The angiogram is definitely the usual best way to assess exactly what is going on, though.
Very best wishes,