PlacentaPregnancyTrophoblastsMothersPlacenta DiseasesPlacenta PreviaPlacenta AccretaPlacenta, RetainedMaternal-Fetal ExchangeChorionic VilliPlacentationPregnancy ProteinsFetusPre-EclampsiaGestational AgeInfant, NewbornPregnancy Trimester, ThirdExtraembryonic MembranesChorionPregnancy, AnimalPregnancy Trimester, FirstMother-Child RelationsFetal Growth RetardationPregnancy ComplicationsPlacental LactogenPlacental CirculationDeciduaChoriocarcinomaUterusFetal DevelopmentPregnancy Complications, InfectiousCesarean SectionInfectious Disease Transmission, Vertical