I have gotten less and less hairy 'down there' in the entire general area as I have aged. AND, weirdo no shit, my pubic hair lost ALL its curl after I became pregnant with ds1. It never ever re-curled, either; it's straight now.
Used to be all curly. Now, just straight. Sigh.
Mine thinned out after DD2. It has yet to fill back in. Still curly though.
Of course it can backfire. After I gave birth and I asked about the hemorrhoid situation, H informed me that he would never complain about his again. So long mystery.
Just to warn y'all...in your 40s, it gets worse (hairier) in new place AND you get a lot more grey. I'm now getting grey eyebrow hairs as well as the pubes, et al.
I have definitely gotten hairier in the butthole region as I have gotten older. And I feel like all my hairy regions have gotten hairier as I have gotten older (more chin hairs, more armpit hairs, etc.). I hate it.