Comparison of Feto-Maternal Outcome in Low-Lying Placenta and Placenta Previa in Scarred Versus Unscarred Uterus: A Prospective Observational Study

Introduction: A scarred uterus has a high incidence of defective implantation of the placenta. This being a major cause of third-trimester haemorrhage, we undertook this study to compare the feto-maternal outcome in women with low-lying placenta and placenta previa having scarred and unscarred uterus. Methods: Women with low-lying placenta and placenta previa at or after 28 weeks of gestation were recruited for the study. A pretested proforma meeting the objectives of the study was prepared, and a detailed history was taken. Maternal and foetal complications were noted and compared between the groups having scarred and unscarred uterus. Results: The incidence of low-lying placenta and placenta previa was significantly lower in women with unscarred uterus (0.91%) compared to scarred ones (3.20%) (p<0.05). The overall blood loss (p≤0.05) and maternal complication rates, viz. placenta accreta syndrome (p=0.014), postpartum haemorrhage (p=0.002), surgical interventions (p=0.09) to manage these complications, and intensive care unit admission (p=0.009), were high in women with scarred uterus. A woman with a scarred uterus had an odds of 4.11 (95% CI: 1.30-13.56) to undergo massive blood transfusion (>5 units of blood) during delivery. There was a significant inverse linear correlation of blood loss during caesarean section and gestational age at delivery. Conclusion: Scarred uterus with placenta previa can independently increase the risk of placenta accreta spectrum, postpartum haemorrhage, blood transfusion, and admission to intensive care units. These women have higher odds of undergoing lifesaving interventions. Such interventions at a lower gestational age of delivery are associated with significant postpartum haemorrhage.