Effect of types of placenta previa on maternal and neonatal outcomes: a 10-year retrospective cohort study

Purpose Through this study, we aimed to evaluate the effects of different types of placenta previa (PP) on maternal and neonatal outcomes. Methods This study was conducted in The Third Affiliated Hospital of Guangzhou Medical University and Tongji Hospital between January 2009 and 2019. PP was traditionally classified into four types, namely low-lying placenta, marginal, partial, and complete PP. Previous studies have classified PP into two types, namely low-lying placenta and PP. Based on our clinical experience, we proposed the classification of PP into three types, for the first time, which included low-lying placenta, "marpartial" (marginal and partial) PP, and complete PP. Multivariate logistic regression analysis was performed to determine the effects of different types of PP on maternal and neonatal outcomes. Results In total, 4490 singleton pregnancies were complicated with PP. In the four-classification method, compared with women with low-lying placenta, women with complete PP had a risk of placenta accrete spectrum disorders, postpartum hemorrhage (PPH), hemorrhagic shock, severe PPH, blood transfusion, hysterectomy, puerperal infection, preterm labor, NICU admission, and low birth weight. There was no difference in maternal and neonatal outcomes between marginal and partial PP, except for increased chances of preterm labor and low birth weight in partial PP. In the two-classification method, PP was the risk factor for most of the adverse maternal and neonatal outcomes, compared with low-lying placenta. Conclusion Complete PP and low-lying placenta were associated with the highest and lowest risks of adverse pregnancy outcomes, respectively, whereas clinically similar outcomes were observed between marginal and partial PP. The three-classification of PP may be practical from the clinical perspective.