Tendency Prediction for Atonic Bleeding Following a Problem-Free Pregnancy

Abstract

Background: The incidence of postpartum hemorrhage (PPH) has increased globally; however, the reasons for this are largely unknown. PPH is potentially fatal and atonic PPH can occur even in low-risk pregnancies. In this study, we aimed to identify the causes of atonic bleeding following a problem-free pregnancy. Methods: One thousand, four hundred sixty-six patients with problem-free pregnancies who experienced total bleeding 2 h after vaginal delivery were divided into two groups based on the amount of blood loss: control group (n = 1,325), with a blood loss of < 800 mL and study group (n = 141) with a blood loss of ≥ 800 mL. Several factors that may correlate with atonic bleeding were divided into three groups: maternal demographic (MD) factors, intrapartum factors, and fatal factors. Comparisons were made between the control group and study group regarding these factors. A multivariate analysis and receiver operating characteristic (ROC) analysis were performed to identify the independent risk factors for atonic bleeding. The continuous net reclassification improvement (NRI) and integrated discrimination improvement (IDI) were also calculated. Results: The independent factors being statistically significant that predicted over 800 mL of atonic bleeding were in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) pregnancies (adjusted odd ratio (OR): 3.63; 95% confidence interval (CI): 2.46 - 5.36; P < 0.001), new-born weight (adjusted OR: 1.0016; 95% CI: 1.0011 - 1.0022; P < 0.001), and the cases of instrumental labor (IL) (adjusted OR: 2.48; 95% CI: 1.64 - 3.77; P < 0.001). ROCs for the final model (area under the curve (AUC): 0.765; 95% CI: 0.724 - 0.806), fatal model (AUC: 0.675; 95% CI: 0.627 - 0.723), intrapartum model (AUC: 0.654; 95% CI: 0.612 - 0.696) and MD model (AUC: 0.615; 95% CI: 0.575 - 0.656) were constructed. The NRI and IDI were 0.733 (95% CI: 0.565 - 0.901; P < 0.0001) and 0.073 (95% CI: 0.051 - 0.90; P < 0.0001) in the fatal model and final model, 0.057 (95% CI: -0.117 - 0.230; P = 0.288) and 0.015 (95% CI: -0.004 - 0.034; P = 0.521) in the MD model, and -0.146 (95% CI: -0.319 - 0.027; P = 0.098) and -0.003 (95% CI: -0.021 - 0.014; P = 0.700) in the intrapartum model. Conclusions: We concluded that IVF/ICSI pregnancies, new-born weight, and IL were independent factors contributing to atonic bleeding. The coincidence of these three factors significantly predicts the likelihood of atonic bleeding. J Clin Gynecol Obstet. 2019;8(2):39-43 doi: https://doi.org/10.14740/jcgo540