title: The complement system in pregnancy.
abstract: Maternal recognition of fetal antigens is well-documented. Antibodies directed against fetal antigens are the rule rather than the exception. Maternal antibodies seem to bind fetal antigens at the placental level and apparently activate the complement system even in normal pregnancy, yet multiple studies confirm an increase in C1q, C4, C3 and CH50 levels in pregnancy and an absence of complement activation. More sensitive assays and a broadened concept of the timing of crucial immunologic events may lead to a greater understanding of the importance of the complement system in pregnancy.
mesh_terms: D002462:Cell Membrane / Q000276:immunology; D003166:Complement Activating Enzymes / Q000378:metabolism; D003167:Complement Activation; D050577:Complement C3-C5 Convertases / Q000378:metabolism; D003170:Complement Pathway, Alternative; D003171:Complement Pathway, Classical; D003165:Complement System Proteins / Q000378:metabolism; D004461:Eclampsia / Q000276:immunology; D005260:Female; D005312:Fetal Blood / Q000276:immunology; D005333:Fetus / Q000276:immunology; D006801:Humans; D011247:Pregnancy
chemical_list: D003165:Complement System Proteins; D003166:Complement Activating Enzymes; D050577:Complement C3-C5 Convertases