The Only Class of Antibody That Can Cross the Placenta

Question

The only class of antibody that can cross the placenta is
A)IgA.
B)IgD.
C)IgG.
D)IgE.

Accepted Answer

IgG is the only class of antibody that can cross the placenta due to its small size and ability to bind to the neonatal Fc receptor (FcRn). This allows for passive immunity to be transferred from the mother to the fetus, providing protection against certain infections until the infant's immune system is fully developed.