No, there's no evidence that IVF itself is associated with higher risks to baby or pregnancy. However, often the underlying causes of the infertility are, and so there may be correlation between IVF and higher risk pregnancies.

My due date was altered with an early dating scan with both pregnancies. I was happy with this as it gave me an extra 3-6 days as I measured 'behind'. (Very handy if you're a 42-weeker). Personally, I reckon there are so many variables in regards to gestation etc, that I would just go with whichever date suits me best.

If you go with a private OB, then you may well have scans that often. We were with DS and after a few checkups asked him to stop all the scans as they were an unnecessary risk.

With regards to prem risk - I don't know of any research on this? I suppose if the mother is older (as many IVF mums are) and she is getting older with each subsequent baby, then that prem risk may well increase. Again, not related to the IVF.