Hawaii - Big Island Activities when pregnant?

So when we initially began planning and booking our honeymoon to Big Island and Maui we had planned to do a bunch of activities on Big Island and relax on/take it easy on Maui.

Well the plans need to be changed as the mrs. is pregnant(will be about 5-6 months when we go) and obviously wont be able to do as much before.

Just curious if anyone else has gone to Hawaii whilst preggers and what kind of activities you would recommend and what you avoided/would avoid.

The only downer for me is that we wont be doing the private volcano trek that some members have taken as we are concerned about the hike and the vog :(

I presume your wife knows her physical limits and won't undertake anything physically too strenuous. Other than that... the only places I would say not to go are the high mountains (above the Visitor Information Station on Mauna Kea, or above the end of the roads on Mauna Loa), or, as you've already noted, up close and personal to volcanic gases.

Most of Hawaii Volcanoes National Park should be just fine; even the Jaggar Museum, which overlooks Halemaumau Crater and its steam plume, doesn't usually get anything nasty unless the prevailing winds die down.

Also fine would be waterfalls (Akaka, Rainbow, etc), botanical gardens, museums, beaches... it all depends on what you're into.

Dan is right about Hawaii Volcanoes National Park. In fact, there are a number of very spectacular hikes which are free of vog and quite doable for a lady who is expecting. The Rangers in the visitors center near the park entrance are exceptionally helpful and friendly, and I know they can make some suggestions that would work for her and still give an amazing experience. FWIW, the Park has closed the areas that are prone to dangerous levels of fumes, and that is a very small percentage of the total area. And finally, congratulations on the addition to your family!

We also did the Fair wind snorkel and helicopter tour when my wife had the big belly:D No problem at all.