I had pre-e with ds2. I was diagnosed somewhere at 36 weeks with mild pre-e. I had some normal swelling, but that's it. No other symptoms. At 37weeks, when a rotating OB decided to look through my chart, they called me in to be induced. I was also put on magnesium. My doctors were really conservative in their approach. My levels were 500 (cutoff of 300), my bp was 140/90.
I ended up with a c/s. I think that was more impatient doctors and not being allowed to even sit up during labor than anything.
Recovery was fine, my bp stabilized the next day (ds was born at 5pm, I was fine the next afternoon).
With pre-e, they will NOT let you go to 40 weeks. The only cure is birth. And because even 'mild' pre-e with no presenting symptoms can get bad quickly (you have seizures, placenta abrupts, etc), they will bring you to as close to term as possible.
Because my labor was so long (22hrs), ds was exposed to the magnesium for a long time as well. Because it's a muscle relaxant, it affected him and his ability to breathe (his muscles were weak, takes muscles to take a breath). He was in NICU for 7 days. It takes babes about 3 days to process the magnesium, so once we were out of the 3 days ds got better by leaps and bounds.
They kept him a bit longer because the last requirement to take a baby home from NICU is that they MUST gain weight.
ETA: if, for any reason your babe needs to be in NICU, you won't be able to visit them until 24hrs after the delivery. For me they kept me on magnesium for 24hrs after delivery. Due to it being a muscle relaxant and the fact I needed to be on IV and cathed while on it, I wasn't mobile. That, to me, was the worst part of the experience.