Describe the hymen and its medicolegal importance.

Anatomy and Normal Variation

• Normal variation is very wide, and the appearance changes with age — oestrogenised and redundant in the newborn, thin and sensitive in childhood, and thickened, elastic and redundant again after puberty. Notches, bumps, tags and clefts are normal findings

Rupture and its Interpretation

• A fresh tear — bleeds, is painful and tender, has red swollen margins, and is usually in the posterior half, at the 5 to 7 o'clock positions, which is where the pressure of penetration falls. It heals within 3 to 7 days, leaving a permanent healed notch or cleft extending to the base
• An old tear — a notch with rounded, smooth, non-tender margins, which cannot be dated
• Causes of hymenal tear other than intercourse — a fall astride a bar, bicycle or edge of furniture; a foreign body or self-instrumentation; medical instrumentation, catheterisation or surgery; masturbation; the use of tampons; athletic activity in rare cases; and in a child, accidental straddle injury, which characteristically injures the anterior structures and the labia rather than the posterior hymen — a distinction of real value
• Causes of an intact hymen despite intercourse — an elastic (distensible) hymen; incomplete or partial penetration; penetration between the labia only, which is legally sufficient; and a well-lubricated, consensual act
• In a child, the hymen is thin, sensitive and unoestrogenised, so penetration is more likely to produce injury, often extensive and involving the perineum — but the absence of injury is still common, and healing is rapid and may be complete

Applied Aspects

• Examine the hymen by gentle separation of the labia in good light, with the survivor comfortable; do not use instruments in a child, and never use a two-finger examination in anyone
• Describe what you see using a clock face and record it on a diagram; "hymen intact" and "hymen torn" are both inadequate and both are read as conclusions they cannot support
• Distinguish a fresh tear from an old notch and from a normal fimbriated margin; the first is datable, the second is not, and the third is not a tear at all
• State explicitly what the finding does not mean — that an intact hymen does not exclude penetration and that a tear does not prove it; without this the court will draw the wrong inference
• In a child, note whether the injury is anterior or posterior; straddle injuries are anterior and involve the labia, whereas penetrative injury falls posteriorly
• Re-examine after 1 to 2 weeks where possible; a healed configuration seen later distinguishes a genuine tear from swelling or a normal variant, and adds materially to the evidence
• Carunculae myrtiformes follow childbirth, not merely intercourse, so their presence and their absence carry quite different weight
• Describe what you see by the clock face; "hymen ruptured" is not a finding, and "a fresh tear at 6 o clock with bleeding margins" is