Don't know darl, But I don't think when it comes to surgery that you'll get to be overly pro active.
They just take it out! LOL
In a vag. birth you have to deliver it so it doesn't need to be cut out obviously.
The Synto ( Syntocinon is a drug, a hormone which is used to stimulate labour, and in the case of the placenta it aids in hastening the seperation of the placenta from the uterus.) So I'd say it just comes away.
Mine looked like one piece, ie didn't look cut or torn.
I can guarantee it doesn't hurt. And there will have been so much tugging etc anyway that you won't know they've removed it.
I didn't even get asked if I wanted the synto. You can say no to it in a Vag. birth some women prefer to let it happen on it's own.
But I'll assume that they just administer it in a cesear because they'd want you back in one piece asap.
Hope that helps more... Not an expert by any stretch of the imagination!