Risk Scoring System for the Prediction of Postpartum Blood Loss over 300 mL at Chiang Rai Regional Hospital

Abstract

Objective: To develop an assessment tool for the prediction of postpartum blood loss over 300 mL and 500 mL after vaginal delivery. Methods: A retrospective case-control study of 504 (72 cases: 432 controls) pregnant women with gestational age of 28 weeks or above who underwent vaginal delivery between 1st October 2015 and 30th September 2016 at Chiang Rai Regional Hospital. The predictors were selected using “Sign OK” selection. The risk scoring system was developed according to the seven steps of clinical prediction model development of Steyerberg. Results: This form included eight predictors: maternal age of 35 years old or above, gestational age over 40 weeks, being nulliparous, curettage in prior pregnancy, gestational hypertensive disorder, hemoglobin level equal to or less than 10 g/dL, fundal height of 38 centimeters or above, and received pethidine for pain relief in the 1st stage of labor. It could predict postpartum blood loss over 300 mL after vaginal delivery with sensitivity of 80.7%, specificity of 60.8%, and the ROC curve equal to 0.71 at the optimal cut-off score of four points or above. However, it could predict postpartum blood loss of 500 mL or above after vaginal delivery with sensitivity of 88.1%, specificity of 54.6%, and the ROC curve equal to 0.71 at the optimal cut-off score of three points or above. Conclusion: This form had an acceptable prediction of postpartum blood loss over 300 mL and 500 mL at the optimal cut-off scores of four points or above and three points or above, respectively.

Keywords

• Risk score
• postpartum blood loss
• vaginal delivery
• Chiang Rai Regional Hospital
• Siriraj Med J 2019;71: 110-116)