Subchorionic Hematoma Volume Measured by Virtual Organ Computer-Aided Analysis in the Prediction of First-Trimester Pregnancy Outcome

This study aimed to assess the association of subchorionic hematoma (SCH) size measured by virtual organ computer-aided analysis (VOCAL) with the first-trimester pregnancy outcome. A total of 139 first-trimester pregnancies from 6 to 12 weeks of gestational age with SCH were included. The circumference, area, and volume of the SCH (Cs, As, and 3DVs) and gestational sac (Cg, Ag, and 3DVg) were automatically calculated by VOCAL. Interobserver agreement was assessed with the intraclass correlation coefficient and Bland-Altman plot. Odds ratios for the clinical and ultrasound characteristics of adverse pregnancy outcomes were estimated by univariate or multivariable logistic regression. There was high interobserver agreement in VOCAL measurements of the SCH and gestational sac (intraclass correlation coefficients, >0.900). By univariate regression analysis, women with adverse pregnancy outcomes were more likely to have vaginal bleeding, a larger As and 3DVs, and higher Cs/Cg, As/Ag, and 3DVs/3DVg ratios (all P < 0.05). In the multivariable regression analysis, a higher 3DVs/3DVg ratio of SCH (odds ratio, 1.034; 95% confidence interval [CI], 1.015-1.053; P = 0.000) and vaginal heavy bleeding had a significant positive relationship with the risk of adverse pregnancy outcomes (odds ratio, 7.846; 95% CI, 1.104-55.737; P = 0.039) remained associated with an increased risk of adverse pregnancy outcomes. With 11.87% as the cutoff, the receiver operating characteristic curve yielded a good predictive performance (area under the curve, 0.713) and high sensitivity (91.18%). The measurements of SCH by VOCAL provide high reliability for estimating the total hematoma burden in first-trimester pregnant patients. A greater volume proportion (3DVs/3DVg) of SCH worsens the pregnancy outcome, and a greater risk of adverse pregnancy outcome also associated with the severity of vaginal bleeding.