Hi, I had my first baby, Leah at 33 weeks, she weighed 4lb13oz and was in special care, they just said to me 'just one of those things' too, when i got pregnant with Maisy they told me it was doubtful she would be early and was under consultant care but she came at 36 weeks, they said this time that some women can be prone to early babies. I'm now carrying baby number 3 (mad arent i?) and am under consultant care. I'm not petite, i'm 5`7. I dont think the size of the mother is relevant, just depends on whether our babies want to see us abit sooner. Maybe the whole 'every pregnancy is 40 weeks' thing should be looked at as no 2 are the same anyway.