Infanticide Practice Questions

Q: In forensic medicine, the hydrostatic test is primarily used to determine which of the following conditions in a deceased infant?

Evidence of infanticide. ### Explanation The **Hydrostatic Test** (also known as the **Raygat’s Test** or **Floatation Test**) is a classic forensic procedure used to determine whether a child was **born alive** or was **stillborn**. This distinction is the cornerstone of investigating suspected **infanticide**. #### Why the Correct Answer is Right: The test is based on the physiological principle that once an infant takes its first breath, the lungs expand and air fills the alveoli. This reduces the specific gravity of the lung tissue (from ~1.050 to ~0.950), making it lighter than water. * **Positive Test (Floating):** Indicates the infant breathed (live birth). * **Negative Test (Sinking):** Indicates the lungs never expanded (stillbirth). In cases of suspected infanticide, proving a "live birth" is the first legal requirement for a homicide charge. #### Why Incorrect Options are Wrong: * **Options A, B, and C (Drowning):** While these involve water, the hydrostatic test is unrelated to the mechanism of drowning. Drowning in adults or children is diagnosed via different findings, such as **Getter’s Test** (chloride levels), **diatom analysis**, or the presence of **fine, leathery froth** at the mouth/nostrils. #### NEET-PG High-Yield Pearls: * **False Positives (Floating despite stillbirth):** Can occur due to **putrefaction** (gas formation) or artificial respiration. * **False Negatives (Sinking despite live birth):** Can occur in cases of **atelectasis**, severe pneumonia, or pulmonary edema. * **Static Test (Fodere’s Test):** Involves weighing the lungs. The **Ploucquet’s Test** compares the lung weight to the total body weight (Ratio is ~1:70 for live birth and ~1:35 for stillbirth). * **Wredin’s Test:** Checks for the presence of air in the middle ear (another sign of live birth).

Q: What is the average weight of a fetal lung after respiration?

60-70 gm. **Explanation:** The weight of the fetal lungs is a critical parameter in forensic pathology used to determine whether a newborn was born alive (live birth) or was a stillbirth. This is based on the physiological changes that occur during the transition from intrauterine to extrauterine life. **1. Why Option C is Correct:** In a full-term fetus, the lungs undergo a dramatic change upon the initiation of respiration. Before birth, the lungs are collapsed and contain only a small amount of fetal lung fluid. Once the infant breathes, the pulmonary vasculature opens, and there is a massive increase in blood flow to the lungs. * **Pre-respiration (Stillborn) weight:** Approximately **30–40 grams**. * **Post-respiration (Live birth) weight:** Approximately **60–70 grams**. The weight nearly doubles due to the increased pulmonary congestion and the presence of air. **2. Analysis of Incorrect Options:** * **Option A (30-40 gm):** This is the average weight of lungs in a **stillborn** fetus (before respiration). * **Option B (40-50 gm):** This represents an intermediate or underweight range, often seen in premature infants or cases of partial respiration/atelectasis. * **Option D (90-100 gm):** This weight is excessive for a newborn and would typically indicate pathology such as pulmonary edema, pneumonia, or hemorrhage. **3. NEET-PG High-Yield Clinical Pearls:** * **Static Test (Foderé’s Test):** Simply involves weighing the lungs. A weight >60g suggests live birth. * **Hydrostatic Test (Raygat’s Test):** Based on the principle that lungs that have breathed will float in water (Specific Gravity changes from ~1.050 to ~0.950). * **Ploucquet’s Test:** The ratio of lung weight to total body weight. * **Stillborn:** 1:70 * **Live born:** 1:35 * **Caution:** Putrefaction can cause a stillborn lung to float due to decomposition gases (False Positive Hydrostatic test).

Q: In a new-born, the autopsy is typically initiated by opening which cavity first?

Abdomen. **Explanation:** In a neonatal autopsy, the **Abdomen** is opened first to assess the **height of the diaphragm**, which is a critical indicator of whether the infant was born alive or stillborn. 1. **Why Abdomen is Correct:** Before any other organ is disturbed, the pathologist must check the position of the diaphragm. In a live-born infant who has breathed, the lungs expand, pushing the diaphragm down to the level of the **5th or 6th rib**. In a stillborn infant, the diaphragm remains higher, at the level of the **3rd or 4th rib**. Opening the abdomen first allows for this measurement without causing artificial pressure changes or air entry into the thoracic cavity. 2. **Why others are incorrect:** * **Head:** Opening the head first is avoided because it can lead to the drainage of blood from the thoracic vessels, potentially interfering with the assessment of heart and lung congestion. * **Chest:** Opening the chest first would immediately alter the intrathoracic pressure, making it impossible to accurately determine the original height of the diaphragm. * **Back:** This is not a standard primary incision site for assessing viability or major organ pathology in neonates. **High-Yield Clinical Pearls for NEET-PG:** * **Hydrostatic Test (Raygat’s Test):** Based on the principle that lungs that have breathed will float in water. It is the most common test for live birth, though decomposition can yield false positives. * **Wredin’s Test:** Presence of air in the middle ear indicates live birth. * **Breslau’s Second Life Test:** Presence of air in the stomach and intestines suggests the infant lived and swallowed air. * **Maceration:** A sterile autolytic process seen in intrauterine death (stillbirth); it never occurs in a live-born infant.

Q: What does a hydrostatic test help to determine?

Live birth. **Explanation:** The **Hydrostatic Test** (also known as the Raygat’s test or Docimasia pulmonum) is a classic medicolegal procedure used to differentiate between a **live birth** and a **stillbirth**. **Why the correct answer is right:** When a child is born alive and takes its first breath, the lungs expand with air. This air reduces the specific gravity of the lung tissue (from ~1.050 to ~0.950), making it lighter than water. In this test, the lungs (or segments of them) are placed in water; if they **float**, it indicates the child breathed (live birth). If they sink, it suggests the lungs are atelectatic (stillbirth). **Why the incorrect options are wrong:** * **Presence of smegma:** Smegma is a sebaceous secretion found under the prepuce or labia; its presence is used to assess the hygiene or physical maturity of a newborn, not lung aeration. * **Criminal abortion:** Evidence for criminal abortion typically involves looking for local trauma to the cervix/vagina, presence of foreign bodies, or chemical irritants, not lung buoyancy. * **Buccal coitus:** This is a form of sexual assault. Diagnosis relies on the presence of semen, acid phosphatase, or DNA swabs from the oral cavity. **High-Yield Clinical Pearls for NEET-PG:** * **False Positive (Floating despite stillbirth):** Occurs due to **putrefaction** (gas formation) or artificial respiration. * **False Negative (Sinking despite live birth):** Occurs in cases of pulmonary edema, pneumonia, or extreme atelectasis. * **Static Test (Fodere’s Test):** Involves weighing the lungs. A live-born lung is heavier due to increased pulmonary blood flow (approx. 1/35th of body weight) compared to a stillborn lung (approx. 1/70th). * **Wredin’s Test:** Examination of the middle ear; disappearance of the gelatinous embryonic connective tissue indicates live birth.

Question 1

In forensic medicine, the hydrostatic test is primarily used to determine which of the following conditions in a deceased infant?

Accepted Answer

Evidence of infanticide

Answer

The presence of dry drowning

Answer

The presence of wet drowning

Answer

The circumstances of near drowning

Question 2

Changes in the middle ear after birth are observed in?

Accepted Answer

Werdin's test

Answer

Ploucquet's test

Answer

Fodere's test

Answer

Breslau's test

Question 3

What is the average weight of a fetal lung after respiration?

Accepted Answer

60-70 gm

Answer

30-40 gm

Answer

40-50 gm

Answer

90-100 gm

Question 4

In a new-born, the autopsy is typically initiated by opening which cavity first?

Accepted Answer

Abdomen

Answer

Head

Answer

Chest

Answer

Back

Question 5

What does a hydrostatic test help to determine?

Accepted Answer

Live birth

Answer

Presence of smegma

Answer

Criminal abortion

Answer

Buccal coitus

Infanticide — MCQs

Infanticide — MCQs

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