The significance of clinical symptoms of subchorionic hematomas, “bleeding first”, to stratify the high-risk subgroup of very early preterm delivery

OBJECTIVE: To investigate the factors that stratify high-risk cases among subchorionic hematomas (SCHs) patients with persistent vaginal bleeding in early pregnancy. MATERIALS AND METHODS: A total of 56 patients who required hospitalization for SCH with vaginal bleeding in early pregnancy were classified into two groups: 1) no hematoma by ultrasonography when vaginal bleeding occurred, and then hematoma was observed by ultrasonography "bleeding to hematoma (BH group, n = 15)" and 2) no vaginal bleeding when hematoma was observed by routine ultrasonography, and then vaginal bleeding occurred later "hematoma to bleeding (HB group, n = 41)". Retrospective cohort study was performed and maternal and neonatal outcomes were evaluated. RESULTS: The duration of SCHs and/or vaginal bleeding was significantly longer in the BH group than in the HB group (mean: 60.8 days [BH group] vs. 33.3 days [HB group], p = 0.015). BH group patients delivered earlier than HB group patients significantly (mean: 27.3 weeks [BH group] vs. 35.6 weeks [HB group], p = 0.0028). The frequency of chronic abruption and oligohydramnios sequence (CAOS) was significantly higher in the BH group than in the HB group (3/15; 20.0% [BH group] vs. 0/41; 0.0% [HB group], p = 0.016). The frequency of sever fetal distress (Apgar score <4 points) was significantly higher in the BH group than in the HB group (4/15; 26.7% [BH group] vs. 0/41; 0.0% [HB group], p = 0.0037). The levels of factor XIII were relatively lower in the BH group than in the HB group (mean: 54.8% (n = 4) [BH group] vs. 76.1% (n = 7) [HB group], p = 0.077). CONCLUSION: The order of the symptoms, bleeding first, is an important feature that reflects the subsequent prolonged duration of SCHs/vaginal bleeding, resulting in very early preterm delivery. Continuous hemorrhage consumes coagulation factor XIII, which further worsen the hemostasis