<prompt> Placenta previa true are:Incidence increases by two fold after LSCSMore common in primiparaMost common in developed countries1 per 1000 pregnancies  <response>: Chances of placenta previa are increased in case of history of prior cesarean sectionThe probability of placenta previa is four times greater in patients with prior cesareans than in patients without uterine scars.Fernando Arias 3e, p 333, 334Therefore, option a is correct partly though because the option says two-fold increaseAs far as - other options are concerned:Option b i.e. it is more common in primipara is absolutely wrong as - placenta previa is more common in multipara.Option c It is more common in developed countries.Now that is incorrect because -Increased family planning acceptance with limitation and spacing of birth, lowers the incidence of placenta previa.Dutta obs 6e, p 243Which clearly means it is less common in developed countries than in developing countries.Option d - Incidence is 1 per 1000 pregnancies:According to Dutta Obs 6e, p 243Incidence of placenta previa ranges from 0.5 to 1 among hospital deliveries.According to 2003 birth certificate data in the US, placenta previa complicated almost 1 in 300 deliveriesWilliams Obs 23e, p 770i.e. option d is incorrect.As far as option e is concerned placenta previa is a cause of APH and not PPH. So, amongst all options - option a is partly correct, so it is the answer of choice here 