Predictive Value of Maternal Parvovirus B19 IgG and Hematologic Profiles for the B19-Induced Miscarriage Risk Score

Abstract

Background: Parvovirus B19 (B19V) is a known cause of first-trimester miscarriages. Although diagnosis using serology has been extensively documented in the literature, no hematology-based risk scoring parameters for the evaluation of pregnant women exposed to B19V infection based on their risk of developing complications.
Objectives: To evaluate maternal parvovirus B19 IgG antibodies and hematological profiles as potential predictive biomarkers for the B19-induced miscarriage risk score. 
Methods: The case-control design included 40 women diagnosed with miscarriage (cases) and 40 women during their full-term pregnancy (controls). Anti-B19 IgG was assayed using ELISA. The following complete blood count values (CBC) were determined: Hb, WBC, RBC, PLT, neutrophils, and lymphocytes. The risk score involves analyzing the independent contributions of B19 serology, RBC indices, and gestational period, using binary logistic regression (odds ratios) in conjunction with Pearson correlation coefficients, ANOVA by gestational periods, and establishing cut-off points based on ROC analysis. 
Results: B19 IgG seropositivity (OR= 7.154; p< 0.001), RBC count (OR = 4.349; p = 0.016), and gestational age (OR = 1.686; p = 0.046) were found to be independent predictors of risk in logistic regression analysis. The prevalence of B19 IgG positivity was significantly higher in miscarriage cases than in controls (67.5% vs. 22.5%; p< 0.001). Significantly lower RBC counts were observed in miscarriages (4.07 ± 0.07 vs. 4.51 ± 0.20 x10⁶/µL; p = 0.017). Miscarriage cases in the first trimester constituted 60% of all cases. The cut-off points calculated via ROC analysis were: 1.85 U/ml (AUC = 0.664; 72.5% specificity) for B19 IgG, 4.21 x10⁶/µL (AUC = 0.654) for RBC, and 1.25 x10³/µL (AUC = 0.635) for WBC. The levels of B19 IgG and lymphocyte count varied significantly in gestational windows (p=.031 and p=.015, respectively).
Conclusions: A clinically useful three-factor risk score, comprising B19 IgG status, RBC count, and gestational age, shows substantial predictive ability for B19V-related miscarriage of early pregnancy. Further validation is required to establish whether this model would be sufficiently accurate to predict B19V-related miscarriage during early-trimester antenatal assessment.