Well, for one thing, I love doing pregnancy massage. (I've written about this elsewhere). In short, for two reasons: one, because the body needs it so much, and two, because it's so effective. Most of the muscular pain and stresses of pregancy are new -- not old, deep-seated problems -- and the body's primed, hormonally, to repair itself especially rapidly. So it's particularly satisfying work.
In Nepal, I'm told, pregnant women get massage daily, as a matter of course. That seems to me like the obvious thing to do.
For Americans, who do so much sedentary work (and even when they sit, usually sit slumped in chairs, so that they're not accustomed even to holding their own upper bodies upright), raising babies and toddlers puts an enormous strain on unprepared backs. Lots and lots of people begin a lifetime of chronic back trouble during this time. I don't think that in America we support child-rearing nearly enough, in general, and in this way, in particular. So you might call this my pro-bono work.