I was using a iud before pregnancy,then after I remove it and get pregnant but I had placentre previa during pregnancy I got a natural birth at seven months and the baby passed away.I want to know the causes and if it can affect me in my next pregnancy.

Placenta previa can affect any pregnancy, you do have a higher risk with your next pregnancy, but it's not impossible not to have a previa.

I'm sorry your baby passed away. Since I was not able to autopsy the baby or the placenta, I cannot tell you why your baby passed. Many times it's not related to the previa, but congenital disorders that are incompatible with life.