Question

Infants are born with a passive immunity that occurs when immunoglobulin antibodies cross the placenta from the maternal circulation prior to birth. Which immunoglobulin is capable of crossing the placenta?

Answer 1

Immunoglobulin G (IgG)

Step-by-step explanation:

There are five classes of human antibodies:

• IgG
• IgM
• IgD
• IgA
• IgE

IgG is the most abundant and the only one capable of crossing the placenta. IgG is present in all body fluids and protects against infections.