Forensic Medicine · Forensic Sexology & Obstetrics

Tests for Live Birth (Hydrostatic, Breslau's, Wreden's)

2 min read · Verified by professors

Hydrostatic Test

Definition: a test performed to determine whether a child has breathed after birth by observing whether the lungs float or sink in water.

Principle

Respiration → Air enters alveoli → Lungs become lighter → Lungs float in water

Procedure

  1. Remove lungs with heart en masse.
  2. Place the lung-heart block in water.
  3. Observe whether it floats or sinks.
  4. Separate lungs from heart; test each lung separately.
  5. Cut lungs into several pieces; place each piece in water.

Interpretation

  • Positive test: whole lungs float, individual lungs float, lung pieces float → child has breathed → suggests live birth.
  • Negative test: lungs sink → no respiration → suggests stillbirth.