Purpose: To evaluate the predictive value of the combination of the Caprini risk assessment model (RAM) and D-dimer for venous thromboembolism (VTE) during puerperium.
Patients and Methods: This was a retrospective case–control study. Thirty-one puerperium patients with VTE were included as cases, and 279 puerperium women without VTE were matched to cases according to age, number of fetuses, birth day and delivery mode at the ratio of 9:1. Demographic data, clinical data and laboratory parameters within postpartum 24 h were collected. Multivariate analysis, employing the forward stepwise model, was conducted to identify independent factors associated with VTE during puerperium. The predictive values of Caprini RAM, D-dimer and their combination were evaluated using receiver operating characteristic (ROC) curve, and the area under curve (AUC) was compared using Z test.
Results: Univariate analysis demonstrated that there were significant differences in D-dimer levels, Caprini score, scarred uterus, adherent placenta, postpartum hemorrhage and intrauterine infection between cases and controls (P< 0.05). Multivariate analysis demonstrated that D-dimer levels (OR: 1.754, 95% CI: 1.237– 3.182), Caprini score (OR: 1.209, 95% CI: 1.058– 2.280), scarred uterus (OR: 1.978, 95% CI: 1.258– 3.794), postpartum hemorrhage (OR: 2.276, 95% CI: 1.334– 4.347) and intrauterine infection (OR: 2.575, 95% CI: 1.463– 4.618) were independently associated with VTE during puerperium with adjustment for adherent placenta and fetal birth weight. The AUCs of D-dimer levels, Caprini score and their combination were 0.748 (SE: 0.030, 95% CI: 0.688– 0.807), 0.647 (SE: 0.035, 95% CI: 0.578– 0.716) and 0.840 (SE: 0.025, 95% CI: 0.791– 0.888). Combination prediction had a higher AUC compared with that of independent prediction (0.840 vs 0.748, Z=2.356, P= 0.009; 0.840 vs 0.647, Z=4.487, P< 0.001) with a sensitivity of 83.9% and specificity of 80.3%.
Conclusion: The combination of the Caprini RAM and D-dimer could significantly elevate the predictive value for VTE during puerperium, and this new tool had the potential in the prediction of VTE during puerperium.

Keywords: venous thromboembolism, puerperium, caprini risk assessment model, D-dimer, prediction