Diluted Russell Viper Venom Test for Lupus Anticoagulant Detection in Pregnancy Population.

BACKGROUND

The association between lupus anticoagulants and pregnancy-related adverse outcomes is highly significant. Widely used in risk assessment, dilute Russell's viper venom time (dRVVT) is a common test for lupus anticoagulants during pregnancy. However, pregnancy induces complex changes in the coagulation system, leading to inconsistent trends in coagulation indicators compared to healthy individuals. This study aimed to investigate the impact of the pregnancy process on dRVVT detection and clinical applications.

METHODS

From July 2021 to February 2022, data from 2,709 pregnant women's dRVVT tests were analyzed, with 71 healthy non-pregnant individuals as a control. Screening tests (LA1), confirmation tests (LA2), and the LA1/ LA2 ratio were compared between early, mid, late pregnancy, and the control group. Using early pregnancy as the observational target, the correlation between the mentioned indicators and pregnancy outcomes were analyzed. Variance analysis and rank-sum tests were employed to assess the consistency, and logistic regression analysis was conducted for data analysis related to outcomes, with p < 0.05 considered statistically significant.

RESULTS

There was no significant difference in LA1 between groups (p > 0.05). LA2 decreased and LA1/LA2 increased with advancing pregnancy (p < 0.05), consistently different from control group (p < 0.05). LA1 and LA1/ LA2 in early pregnancy were correlated with pregnancy outcomes and served as independent prognostic factors for adverse pregnancy outcomes (p < 0.01), with LA1/LA2 being the optimal outcome prediction indicator.

CONCLUSIONS

As pregnancy progresses, LA2 decreases significantly, while LA1 remains unchanged. Existing dRVVT standards for adults may falsely elevate lupus anticoagulant detection during pregnancy. Establishing pregnancy-specific criteria for dRVVT is essential.