Incidence of placenta previa in cesarean section

Aim To study the incidence of placenta previa in previous cesarean section and compare it with incidence of placenta previa in women with no prior cesarean section. Background There is an evident literature support which suggest that the chances of placenta previa are not only more in patients who had a previous history of cesarean section but the chances also increases with the number of cesarean section in past. The overall incidence of placenta previa is 0.2-0.5% in western studies. It may be more in Indian population. As there were not many studies on this important topic from Indian subcontinent. Material Methods Total 484 patients with history of previous Lower Segment cesarean Section were selected for study purpose. 496 subjects with no previous history of cesarean section were selected for control purpose. Clinical examination and USG was done at 28 weeks to detect placenta previa. Results Ten cases of placenta previa were found in the study group and incidence of placenta previa was calculated to be 2% in this group compared to incidence of only 0.6% i.e. 3 cases in control group (p< 0.05). Also the chances of finding placenta being morbidly adherent were increased in the study group as we found 2 cases of placenta increta and 3 cases of placenta accreta among these. Conclusion Incidence of placenta previa is high in patients with previous cesarean section as well as chances further increases with the successive increase in number of cesarean section in past.