Amy - a friend of mine is going to use PGD as her hubby has a rare genetic conditions where they have a 50% chance of passing it on to any baby, if they concieve naturally.

I dont see this as "messing with mother nature" at all - I see it as them doing the best they can for their baby by ensuring that they do not pass on this condition.

Be aware though - it is costing them in the vicinity of $12 - $15 k. Hopefully that round of IVF works - if not, they will have to find the $$ all over again.