IMMUNOLOGY

Detailed explanation-1: -Placental transfer of maternal IgG antibodies to the fetus is an important mechanism that provides protection to the infant while his/her humoral response is inefficient. IgG is the only antibody class that significantly crosses the human placenta.

Detailed explanation-2: -The researchers found that the most common class of antibodies in the blood, known as immunoglobulin G (IgG) antibodies, appeared to transfer readily from the mother’s blood across the placenta.

Detailed explanation-3: -Abstract. THE IgG of the neonatal human infant is almost entirely derived by selective transplacental passage of maternal IgG, but IgA and IgM are considered incapable of transplacental passage.