Three members of our regular gaming group have had babies in the last 8 months. Since each of these members are married to another member, that means six of us are passing around babies as often as dice at each session. We also have a two year old and a six year old running around causing havoc, and occasionally, the gaming must pause while a parent utters one of those priceless gems such as, "Big boys wear pants."
Nonetheless, our intrepid party continues.
We are primarily in the mid-twenties to mid-thirties range, meaning we are in the prime baby-having years. Most of us are married. This means more planning.
We spend more time planning the games, because the addition of spouses (and one teenager) means a very large group. We plan meals, as none of us care to go overly long without munching something, and typical gaming fare usually is not enough. We plan ways to entertain the two little boys so that the adults can have fun playing their own games. We pack diapers.
The results of all this planning are games that tend to have longer, more drawn out story arcs. Also, the characters provide their own motivations have their own goals, so if the DM doesn't have a lot planned, the characters kind of "hook" themselves onto a new adventure. The DM just has to keep up. Luckily, our DM's have played long enough to be able to do that, and do it well.
We have found that we have to split our gaming sessions up. The biggest group, the one with *all* the kiddos, meets every other week, so that we have more time for planning. A smaller group meets on the "off" weekends, and runs for 2-3 hours. The smaller group alternates between two campaigns, run in two different systems by two different DM's, once again, so that the DM's have more time for planning.
So for us, that's the only real difference: a sharp rise in the amount of time spent planning.