<prompt> Placenta pre true are:incidence increases by two fold after LSCSMore common in primiparaMost common in developed countries1 per 1000 pregnancies  <response>: Prior surgery on the uterus especially Caesarean section increases the incidence of placenta prae two or three fold.The combination of a prior Caesarean section with an anterior placenta prae is paicularly dangerous refer pgno:129 sheila textbook of obstetrics 2nd edition 