I am an experienced and confident skier, and am currently 26 weeks. So I won't be skiing this season anyway, as am due mid-Feb, so won't be able to ski before that or immediately after.
I know a lot of people who have skied in early pregnany, either before they were really sure they were, and up to about 12 weeks. A lot of the time they have been with family/groups and their friends have skied in a protective 'diamond' formation around them. Also ski instructors often ski late into pregnancy as they have very little in the way of maternity leave and so as it's their livelihood they need to.
However, there is no mitigating all the risks, there are some irresponsible and unsafe people on the slopes, and especially February, which is high season, there are the risks of just the sheer volume of people on the slopes.
So say I was due in June for example, I probably still wouldn't, because I'm just too physically tired to enjoy that kind of thing. Getting up and down stairs is an effort some days, never mind clumping around in ski boots in and out of lift stations up and down steps etc. Let alone the actual skiing itself. Am needing to drink quite a lot more water and eat odd things at irregular times, and I just don't think I would enjoy a ski hol at the moment, and this is someone who goes three times a year and used to live in Austria and is totally hooked.
I would go on the holiday though, relax in the sun/snow, have some pamper treatments and enjoy the break.
D