The effect of previous obstetric interventions in the outcome of placenta previa

Background: Increase in the incidence of prior caesarean section and other obstetric interventions have contributed to a rise in the number of pregnancies complicated by placenta previa and its associated adverse maternal and perinatal outcome. This study compared the incidence of placenta previa, associated risk factors, placental position, complications and feto-maternal outcome in scarred and unscarred uterus. Objective of present study was to compare the antepartum, intrapartum and postpartum complications in placenta previa between previously scarred uterus and unscarred uterus.Methods: This was a prospective “nested” case control study for a period of 18 months, conducted at SAT Hospital, Medical College, Thiruvananthapuram with diagnosed cases of placenta previa with previously scarred uterus and without a previously scarred uterus. Statistical method used for analysis was chi-square test and students test wherever appropriate. P<0.05 was taken as significant.Results: In this study of 242 patients, there were 134 in the case group and 108 in the control group. The major types of previa were seen in the previously scarred uterus compared to unscarred uterus (55.9% versus 37.9%). Occurrence of recurrent APH (58.9% Vs 41.6%), postpartum haemorrhage (69.4% Vs 48.1%), adherent placenta (5.9% versus 0%) and need for additional operative procedures (66.4% versus 53.7%) including obstetric hysterectomy, need for blood transfusions, postoperative complications (9.7% versus 1.8%), long postoperative hospital stay were all significantly associated with cases of placenta previa in previously scarred uterus.Conclusions: The primary caesarean rate needs to be reduced in order to reduce future pregnancy problems like adherent placenta and caesarean hysterectomy. Such patients need early referral and management in a tertiary health centre with all facilities available for a better maternal and neonatal outcome