1. Risk evaluation for PPH and Reserve plan; 2.Assess blood loss using Estimated Blood Loss Form and amnion fluid collection drape; 3. Satisfy any of the following conditions: i. If the estimated blood loss reaches 500ml but is less than 1000ml, and any of the following abnormal indicators are present; ii. If the estimated blood loss reaches 1000ml, no other indicators need to be considered:

1. Lack of uterine contractions

2. Persistent bleeding

3. Shock index (heart rate/systolic blood pressure) was greater than 0.9 Initiate the following protocols①, ②, ③, ④

   • Maintain uterus tone (Administration of Oxytocin and second-line medications to promote uterine contraction)

     • Intravenous infusion ③ Administered tranexamic acid

       • Multi-methods and Multi-disciplinary

The usual care group does not receive a PPH risk assessment and estimates blood loss visually and used various interventions for postpartum hemorrhage in accordance with local or national guidelines.

1. Risk evaluation for PPH and Reserve plan;

2. Assess blood loss using Estimated Blood Loss Form and amnion fluid collection drape;

3. Satisfy any of the following conditions: i. If the estimated blood loss reaches 500ml but is less than 1000ml, and any of the following abnormal indicators are present; ii. If the estimated blood loss reaches 1000ml, no other indicators need to be considered: 1） Lack of uterine contractions 2） Persistent bleeding 3）Shock index (heart rate/systolic blood pressure) was greater than 0.9 Initiate the following protocols①, ②, ③, ④

   • Maintain uterus tone (Administration of Oxytocin and second-line medications to promote uterine contraction)

     • Intravenous infusion ③ Administered tranexamic acid ④ Multi-methods and Multi-disciplinary

defined by a calculated estimated blood loss > 1000 mL [Calculated estimated blood loss = estimated blood volume × (preoperative hematocrit - postoperative hematocrit)/preoperative hematocrit (where estimated blood volume (mL) = weight (Kg) × 85)] or red blood cell (RBC) transfusion before day 2 postpartum .

Calculated estimated blood loss = estimated blood volume × (preoperative hematocrit - postoperative hematocrit)/preoperative hematocrit (where estimated blood volume (mL) = weight (Kg) × 85)]