I had one on our babymoon in Daylesford.

It cost a fair whack, but I love massages, and it was worth it.

They had these thick foam/latex/whatever pads that went on top of the bed, and had a hole where the belly went through! So belly was suppoted by the bed, but you were lying on the pads - worked well. And it meant that they could massage all shoulders, back, thighs, etc.

They only used particular oils and techniques and avoided certain spots.

But I had to ring around a bit to find places which have people who specialise in pg massages, as I didn't want to take any risks.