A Multicenter, Retrospective Comparison Study of Pregnancy Outcomes According to Placental Location in Placenta Previa.

Background: We investigated the association between placental location and pregnancy outcomes in placenta previa. Methods: This multi-center retrospective study enrolled 781 women who delivered between May 1999 and February 2020. We divided the dataset into anterior (n = 209) and posterior (n = 572) groups and compared the baseline characteristics and obstetric and neonatal outcomes. The adverse obstetric outcomes associated with placenta location were evaluated using a multivariate logistic analysis. Results: Gestational age at delivery in the anterior group (253.0 ± 21.6) was significantly lower than that in the posterior group (257.6 ± 19.1) (p = 0.008). The anterior group showed significantly higher parity, rates of previous cesarean section, non-vertex fetal positions, admissions for bleeding, emergency cesarean sections, transfusions, estimated blood loss, and combined placenta accrete spectrum (p < 0.05). In the multivariate analysis, the anterior group had higher rates of transfusion (OR 2.23; 95% CI 1.50-3.30), placenta accreta spectrum (OR 2.16; 95% CI 1.21-3.97), and non-vertex fetal positions (OR 2.47; 95% CI 1.09-5.88). Conclusions: These findings suggest that more caution is required in the treatment of patients with anterior placenta previa. Therefore, if placenta previa is diagnosed prenatally, it is important to determine the location of the body and prepare for massive bleeding in the anterior group.