TrisomyPlacentaDown SyndromePregnancyPlacenta DiseasesPlacenta PreviaPlacenta AccretaChromosomes, Human, Pair 18KaryotypingPlacenta, RetainedChromosome DisordersChromosomes, Human, 16-18Chromosomes, Human, Pair 21Prenatal DiagnosisChromosomes, Human, Pair 13MosaicismPregnancy Trimester, FirstTrophoblastsAbnormalities, MultipleNuchal Translucency MeasurementUltrasonography, PrenatalPregnancy Trimester, SecondChorionic Gonadotropin, beta Subunit, HumanChromosomes, Human, 13-15Nondisjunction, GeneticChromosomes, Human, 6-12 and XChromosome AberrationsFetal DiseasesMaternal AgeChorionic VilliGestational AgePregnancy-Associated Plasma Protein-AFetusNasal BoneChromosomes, Human, 21-22 and YMaternal-Fetal ExchangePregnancy ProteinsPregnancy, High-RiskAneuploidyChromosome BandingAmniocentesisDermatoglyphicsCrown-Rump LengthIn Situ Hybridization, FluorescencePlacentationChromosomes, Human, Pair 8Translocation, GeneticChorionic Villi SamplingMonosomyChromosomes, Human, Pair 12Pregnancy Trimester, ThirdChromosomes, Human, Pair 7Chromosomes, Human, 19-20Chromosomes, Human, 4-5Infant, NewbornNeckFetal Growth RetardationPre-EclampsiaAmniotic FluidChromosomes, Human, 1-3Intellectual DisabilityExtraembryonic MembranesChorionFetal DeathPregnancy, AnimalPlacental LactogenDeciduaCytogenetic AnalysisPlacental CirculationCytogeneticsForeheadAbortion, EugenicFetal HeartChoriocarcinomaSyndrome