A hand-held, manual, obstetrical, surgical instrument intended to cut the outlet of the vagina in childbirth so as to facilitate the birth of the child (also known as perineotomy). It comprises two pivoted blades that are usually provided with a finger and thumb ring-handle and which cut with a shearing action (i.e., the blades cut as the sharpened edges pass one another as they are closed). It is typically made of high-grade stainless steel and is available in various designs and sizes; the blades are typically angled, have different shapes, and may be serrated. This is a single-use device.