Caput succedaneum

Caput succedaneum is a benign neonatal condition involving a serosanguinous (containing blood and serum), subcutaneous, extra-periosteal fluid collection with poorly defined margins caused by the pressure on the presenting part of the fetal scalp by the vaginal walls and uterus as the infant passes through a narrowed cervix during delivery.

It involves bleeding below the scalp and above the periosteum.