To establish a preliminary scoring model for postpartum hemorrhage (PPH) in pregnant women with placenta previa status (PPS) after artificial termination of pregnancy (ATP).

A total of 142 pregnant women with PPS who underwent ATP in Chengdu Women′s and Children′s Central Hospital from January 2010 to December 2018 were selected as research subjects by retrospective method. Chi-square test was used for univariate analysis of influencing factors of PPH in pregnant women with PPS after ATP. Then, with the consideration of existing research results, clinical experience and the factors with statistically significant differences in the results of univariate analysis, 5 possible influencing factors of PPH in pregnant women with PPS were analyzed by multivariate unconditional logistic regression analysis. According to the OR value of influencing factors in the results of logistic regression analysis, scores were assigned to the influencing factors of PPH. According to this scoring standard, the total PPH risk scores of all pregnant women were calculated. The receiver operator characteristic (ROC) curve of total PPH risk score for predicting the occurence of PPH in pregnant women with PPS was drawn, and the area under the ROC curve (ROC-AUC) was calculated. According to the maximum principle of Youden index, the optical critical value of total PPH risk score for predicting the occurrence of PPH in pregnant women was determined. The procedures followed in this study were in line with the requirements of the World Medical Association Declaration of Helsinki revised in 2013.

①Univariate analysis of the influencing factors of PPH in pregnant women with PPS showed that factors with statistically significant difference included the history of ATP (≥3 times or <3 times), body mass index (BMI)≥25 kg/m² or <25 kg/m^2, cesarean section history, types of PPS (marginal, partial or complete PPS), and status of placenta accreta (without placenta adhesion, placenta adhesion or placenta accreta). ②Multivariate unconditional logistic regression analysis was performed on the above 5 possible influencing factors of PPH, and the results showed that cesarean section history (OR=18.865, 95%CI: 4.013-88.671, P<0.001), complete PPS (OR=20.148, 95%CI: 3.387-119.846, P<0.001), placenta adhesion (OR=44.045, 95%CI: 9.772-198.523, P<0.001) and placenta accreta (OR=87.494, 95%CI: 11.685-655.111, P<0.001) all were independent risk factors for PPH in pregnant women with PPS, and they were signed to 1 score, 1 score, 2 scores ad 4 scores, respectively according to the OR value of these independent risk factors of PPH. The ROC-AUC of total PPH risk score for predicting the occurrence of PPH in pregnant women with PPS was 0.926 (95%CI: 0.876-0.975, P<0.001). According to the maximum principle of Youden index, the optimal critical value for total PPH risk score for predicting PPH in pregnant women with PPS was 3 scores. At the same time, the sensitivity of total PPH risk score for predicting PPH in pregnant women with PPS was 83.3%, the specificity was 92.5%, and the accuracy was 88.0%.

The predictive scoring model of PPH in pregnant women with PPS established in this study can effectively predict the risk of PPH after ATP, which is beneficial to individual choice of ATP. Because this study just is a single-center and retrospective research, multi-center, large-sample and prospective studies are needed to further confirm the clinical value of this scoring model.