Which description correctly defines a subchorionic bleed?

• A. Pooling of blood between the myometrium and gestational sac
• B. Bleeding between placenta and myometrium
• C. Bleeding between endometrium and myometrium
• D. Bleeding within fetal chorionic tissue

Answer: (A)

Subchorionic bleed is a collection of blood that forms between the chorionic membranes surrounding the gestational sac and the uterine wall (the myometrium/decidua). On ultrasound this appears as a pooling of blood right at the edge of the gestational sac, outside the placenta, often described as a crescent-shaped hematoma adjacent to the sac. This location—between the myometrium and the gestational sac—is what defines a subchorionic hematoma.

This is distinct from placental abruption, where bleeding occurs between the placenta and the myometrium; or a bleed between the endometrium and myometrium (subendometrial/endo-myometrial hematoma); or bleeding within fetal chorionic tissue (intrachorionic). Understanding the exact plane of the blood helps clinicians assess potential implications for pregnancy.