Thanks Friendly, London and Scottish! (Friendly, London and Scottish sounds a little like the name of an insurance firm).
I've started to use bio oil and palmers stretch mark cream (one morning, one night) on my stomach, bulked out with a bit of baby oil on hips/boobs. I don't expect to avoid stretch marks as I got some in puberty, but I would like to at least try and minimise. We'll see in 6 months whether it makes a difference...