In medical terms, a chignon is a temporary swelling left on an infant's head after a ventouse suction cap has been used to deliver him or her. It is not a sign of serious injury and may take as little as two hours or as long as two weeks to disappear.

A vacuum extraction is a type of assistance used during vaginal delivery by an obstetrician or midwife when the second stage of labor, where the cervix is fully dilated allowing for fetus delivery, is stalled.

During vacuum extraction, the cup is attached to the infant's head, exposing the infant's head to trauma due to the vacuum pressure and pulling force involved in the procedure. This form of assisted delivery is typically required when the labor is stalled due to difficulties in the stages of labor arising, such as when the infant's head found too high in the birth canal. Due to prolonged pressure and tension, this induces an accumulation of interstitial fluid (the fluid that surrounds cells) as well as possible minor hemorrhages, ultimately resulting in scalp swelling.

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