Interpregnancy interval as a risk factor for placenta accreta.

Abstract To determine if the interval from a previous delivery or cesarean to the next conception differs between patients with abnormally adherent placentas as compared to those with normally implanted placentas. We identified all histologically confirmed placentas--accreta, increta, and percreta--at our hospital from 1992-1999. Subjects were excluded for primigravidity in the affected pregnancy or inability to identify matched controls. Cases were matched to the next three consecutive women delivering for maternal age (> or = 35 years or