All I know is that my Ob would not schedule my c-section till I was past 38wks as they run the risk of dates being out and they actually end up with a premmie, unless there was something wrong with baby or me, OR I went into labour. I was a scheduled c-section and DS2 was born at 38wk5d. The Ob only operated on certain days and the week before I would have been 37wk2d and he would not schedule me that early. HTH