Question

At the time of birth, presence of which antibody indicates the infection of foetus (intrauterine infection)?

• A. IgG
• B. IgD
• C. IgM
• D. IgA

Answer 1

The correct option is A IgG

Antibodies are immunoglobins (Ig) which are produced in response to antigenic stimulation. Each antibody molecule has four peptide chains, two long chains called heavy or H chain and two short chains called light or L chains. Hence an antibody is represented as $H_2{L}_2$. Different types of antibodies are produced in our body. IgA, IgM, IgE, IgG are some of them. At the time of birth, presence of IgG indicates the infection of foetus (intrauterine infection). IgG is the most abundant class of antibody. It can cross the placenta. It provides natural immunity in the foetus.