These pants are really comfy. Definitely get pre pregnancy size as they will fit true to size. Prepregnancy I was an AU 10-12 (Small to Med) and a large towards the end of pregnancy in my maternity tights. If you want a looser fit then size up from regular size. The only thing I don't like is that the front part below the band is sewn in a way that it pulls inwards (towards the unseen) rather than lay flat. So you end up with a bit of a V shape. But the band is very thick and comfy and adjustable with the drawstring over a post partum tummy.