My kids were all born before the chicken pox vaccine was around, and I do still remember some of the moms around having "pox parties" when one of their children came down with it. I suppose it seemed like a good enough idea at the time...My older two actually had it just about a week before their younger brother was born, and I did worry that he would end up exposed to it in his first days. He ended up getting it when he was about 3, though.
On the one hand, it seems like no biggie when you look at the statistics of complications in the age bracket which typically gets it, and especially when compared to that of people who get it as adults, but I'd hate to even imagine being the mother in one of those very rare cases where it does, in fact, cause major complications or death. Then, too, there is always the risk of shingles later on, which can be a WHOLE lot nastier. My father in law got shingles about 4 years ago, just as he was on the recovery end of a series of health problems which had been sorted out and would have given him quite a few more years of quality life, but since then, he has been almost bedridden due to pain from nerve damage which nothing seems to be able to help.