# Evaluation of the clinical performance of a risk scoring model for venous thromboembolism prophylaxis in cesarean section for a largely Chinese population

## TL;DR

A new risk scoring model for preventing blood clots after cesarean sections in Chinese women reduced clot incidents without increasing bleeding risks.

## Contribution

A new risk assessment score tailored for Chinese women undergoing cesarean sections was developed and validated.

## Key findings

- The new protocol reduced postpartum VTE incidence from 0.33% to 0.1%.
- Pharmacologic prophylaxis was used in only 3.25% of patients under the new protocol.
- No significant increase in bleeding complications was observed with the new protocol.

## Abstract

Recommendations for venous thromboembolism (VTE) prophylaxis after cesarean section (CS) from authoritative guidelines differed significantly and may not be applicable to Chinese population.

This study aimed to evaluate the performance and safety of an adapted risk score prophylaxis protocol in a largely Chinese cohort.

The risk assessment and preventive care for VTE for CS protocol was implemented from May 2017 for all patients undergoing CS. Those with moderate risk (VTE score, 2) would be prescribed mechanical prophylaxis using pneumatic cuff, and those with high risk (VTE score, ≥3) would be prescribed pharmacologic prophylaxis with low-molecular-weight heparin in addition to the pneumatic cuff. In this retrospective cohort study, the outcome of patients with CS from the time of implementation of the protocol to December 2024 (7.5 years) was compared with that of a preprotocol group with no prophylactic measures from January 2014 to April 2017.

Among 4803 patients with CS in the protocol period, 633 (13.2%) women were prescribed mechanical prophylaxis and 156 (3.25%) patients required pharmacologic prophylaxis. Recoding the risk scores under the Royal College of Obstetricians and Gynaecologists or American College of Chest Physicians guidelines showed that 78.9% and 27.1% would require pharmacologic prophylaxis, respectively. There were 5 patients with VTE events in the protocol group compared with 11 among 3309 CS patients in the preprotocol group. The observed incidence of postpartum VTE significantly dropped from 0.33% to 0.1% after the implementation of the protocol (P = .043), while there was no increase in bleeding complications (0.96% in the preprotocol period vs 0.76% in the protocol period).

Implementation of a standardized thromboprophylaxis protocol adapted for cesarean deliveries in our local obstetric population maintained pharmacologic thromboprophylaxis at a low rate and did not result in an increase in bleeding complications. A lower incidence of VTE was observed after implementation of the protocol than that in the preprotocol period.

•Pregnancy and CS increase the risk for VTE.•A new risk assessment score is proposed for women undergoing CS.•The new score maintained the use of pharmacologic thromboprophylaxis at a low rate.•A lower incidence of VTE was observed after the implementation of the protocol.

Pregnancy and CS increase the risk for VTE.

A new risk assessment score is proposed for women undergoing CS.

The new score maintained the use of pharmacologic thromboprophylaxis at a low rate.

A lower incidence of VTE was observed after the implementation of the protocol.