IMMUNOLOGY

Detailed explanation-1: -Naturally acquired passive immunity occurs during pregnancy, in which certain antibodies are passed from the maternal blood into the fetal bloodstream in the form of IgG. Antibodies are transferred from one person to another through natural means such as in prenatal and postnatal relationships between mother and child.

Detailed explanation-2: -During the last 3 months of pregnancy, antibodies from mothers are passed to their unborn babies through the placenta. This type of immunity is called passive immunity because the baby has been given antibodies rather than making them itself.

Detailed explanation-3: -IgG is the only antibody class that significantly crosses the human placenta. This crossing is mediated by FcRn expressed on syncytiotrophoblast cells.

Detailed explanation-4: -Passive immunity Unborn and newly born babies are protected by antibodies from the maternal immune system. These antibodies are shared in two ways: across the placenta and in breast milk.

Detailed explanation-5: -Immunoglobulin G (IgG) is the only antibody isotype that can pass through the human placenta, and is the most common antibody of the five types of antibodies found in the body. IgG antibodies protects against bacterial and viral infections in fetuses.