Meta-analysis of subchorionic hemorrhage and adverse pregnancy outcomes
The purpose of this study was to determine whether subchorionic hemorrhage is associated with increased adverse pregnancy outcomes of preterm delivery, spontaneous abortion, and abruption. PUBMED databases were searched for case control, cohort, and cross-sectional human studies that investigated the relationship of ultrasound detected subchorionic hemorrhage and adverse outcomes of preterm delivery, spontaneous abortion, and abruption. Data were extracted by two independent investigators. Nine studies were included in the pooled meta-analysis. Relative risk estimates (RR) and 95% confidence intervals (CI) were pooled across studies. Subchorionic hemorrhage was associated with preterm delivery (pooled RR = 1.64; 95%CI 1.41-1.89), spontaneous abortion (pooled RR = 2.59; 95% CI 2.34-3.25), and abruption (pooled RR = 3.16; 95% CI 2.32 – 4.31). This study suggests that early pregnancy subchorionic hemorrhage may increase the risk of preterm delivery, spontaneous abortion, and abruption. Women may be advised of increased adverse outcomes associated with subchorionic hemorrhage.