& x20;Which type of immunity is transferred from the mother to the fetus through the placenta? - AIIMS M.Sc. Nsg Entrance exam-2026

AIIMS M.Sc. Nsg Entrance exam-2026

Applied Microbiology & Infection control

Easy

Appeared in: AIIMS M.Sc. Nsg Entrance exam-2026

Explanation

Passive natural immunity involves the transfer of pre-formed antibodies from one individual to another.
Specifically, it refers to the transfer of maternal antibodies, primarily Immunoglobulin G (IgG), across the placenta to the fetus.
This process provides the newborn with immediate but temporary protection against pathogens to which the mother has been exposed.
This immunity wanes over the first few months of life as the infant's own immune system matures.

Option A: Innate immunity is the non-specific, inborn defense system of the body (e.g., skin, mucous membranes, phagocytic cells). It is not acquired or transferred from the mother via the placenta.
Option B: Active natural immunity develops when a person's own immune system produces antibodies in response to an infection. The fetus does not get an infection to develop this immunity from the mother.
Option D: Acquired immunity is a broad category that encompasses both active and passive immunity. While passive natural immunity is a type of acquired immunity, 'Passive natural immunity' is a more specific and precise answer to the question.

Visual 1: Diagram: A diagram illustrating the transfer of IgG antibodies from the maternal circulation, across the placenta, and into the fetal circulation.
Visual 2: Flowchart: A flowchart categorizing the different types of immunity (Innate vs. Acquired, then Active vs. Passive, and finally Natural vs. Artificial) with examples for each branch.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Types of Immunity as background academic context rather than a clinical decision trigger.
Understanding passive natural immunity is crucial for neonatal care. It explains why newborns have protection against certain diseases for the first few months.
It underscores the importance of maternal health and vaccination. When a mother is vaccinated (e.g., with Tdap), she produces antibodies that are passed to the fetus, protecting the baby from diseases like pertussis (whooping cough) in early life.
What if the question asked about immunity from breast milk? The answer would still be passive natural immunity, but the primary antibody transferred is IgA, which protects the infant's mucosal surfaces.

How to Approach the Question

First, identify the key terms in the question: 'transferred from mother to fetus' and 'placenta'.
Recognize that 'transferred' implies a passive process, as the fetus is receiving protection, not creating it.
Differentiate between 'active' (body makes its own antibodies) and 'passive' (antibodies are received from an external source). The question describes a passive process.
Differentiate between 'natural' (occurs through natural processes like pregnancy or infection) and 'artificial' (occurs through medical intervention like vaccination or antibody injection). The transfer via the placenta is a natural process.
Combine these concepts: The immunity is both 'passive' and 'natural'. This leads directly to the correct option.
Evaluate all options to confirm the choice. 'Acquired immunity' is too broad, and 'Innate' and 'Active' are incorrect mechanisms.

Concept Tested & Keywords

QEUrTSC6t0QC5L85E8nBM