3rd trimester ladies....sono's and fainting

It seems I can't even be on my back for more than 5 minutes without feeling like I am going to faint. The last 3 times I have had sono's, we've had to stop so that I can get up, drink water, smell alcohol (they said ammonia may have been too much since I was already feeling sick), etc. I am high-risk due to carrying twins, so I get sono's every 2 weeks now. Two nursers came into the room because I couldn't see (everything was black) yesterday and the tech got nervous. Since it's twins, it takes awhile to do all the measurements. After this incident I had to sit almost all the way sitting up, so the measurements are not really accurate. I'm 29 weeks and have 9 weeks to go before a scheduled c-section, which means 4-6 more appointments. Yikes! Did this happen to you and what did you do?
Also, my Mom mentioned what am I going to do when I actually have the c-section because I'll be laying on my back. I just said that I'll be numb and hopefully won't know what's going on. But now that sounds stupid. I know they get the babies out fast, so maybe it won't be so bad. But any thoughts on this?

Re: 3rd trimester ladies....sono's and fainting

Is it possible for them to raise your head a bit. When I had my twins back in 2005 my head was always slightly elevated. Like a semi-sitting position.

As far as the c-section, most OR tables are slightly tilted to the side (I am an OB nurse) so you are not putting alot of pressure on your major vessels. HTH.