My GP checks at 6 wk check. I didn't get it (not that I knew of, loads of checks because I am old, out of area and had emcs both times) but I had middling size babies and the first was footling breech anyway. I also went to pg Pilates classes from about 18 weeks in both pg.
My friend had massive (9 lb +) babies and got it all three times. Our hospital offers post natal exercise classes (with childcare!) to mums of babies that were more than 9lb who got distatis.