title: The placental transfer of IgG subclasses in human pregnancy.
abstract: Total IgG concentrations and the concentrations of the four subclasses of IgG were estimated in thirty-four pairs of maternal and foetal sera from pregnancies of various gestations ranging from 28 to 42 weeks using the method of radial immunodiffusion. It was found that: (1) all subclasses of IgG cross the human placenta freely, (2) foetal levels of IgG and each subclass of IgG exceed maternal levels in full-term pregnancies and (3) there was a close linear relationship between gestational age and the placental transfer of IgG and each of its subclasses.
mesh_terms: D005260:Female; D005312:Fetal Blood / Q000276:immunology; D005865:Gestational Age; D006801:Humans; D007074:Immunoglobulin G / Q000145:classification / Q000378:metabolism*; D007231:Infant, Newborn; D008431:Maternal-Fetal Exchange; D010920:Placenta / Q000276:immunology; D011247:Pregnancy
chemical_list: D007074:Immunoglobulin G