TrisomyPregnancyDown SyndromePregnancy OutcomePregnancy ComplicationsPregnancy, AnimalPregnancy Trimester, FirstPregnancy, EctopicPregnancy Trimester, SecondKaryotypingChromosomes, Human, Pair 18Pregnancy Trimester, ThirdChromosome DisordersPrenatal DiagnosisPregnancy RatePregnancy, High-RiskChromosomes, Human, 16-18Ultrasonography, PrenatalPregnancy Complications, CardiovascularChromosomes, Human, Pair 21Pregnancy TrimestersPregnancy TestsChromosomes, Human, Pair 13Maternal AgePregnancy, MultipleMosaicismChorionic Gonadotropin, beta Subunit, HumanGestational AgeAbnormalities, MultipleNuchal Translucency MeasurementPregnancy in DiabeticsPregnancy, TubalAbortion, SpontaneousFetal DiseasesPregnancy Complications, NeoplasticPregnancy in AdolescenceInfant, NewbornPregnancy Complications, InfectiousChromosome AberrationsChromosomes, Human, 13-15Pregnancy ProteinsNondisjunction, GeneticChromosomes, Human, 6-12 and XPregnancy-Associated Plasma Protein-APregnancy, UnplannedAmniocentesisPregnancy, UnwantedNasal BoneCrown-Rump LengthFetal DeathAneuploidyChromosomes, Human, 21-22 and YPlacentaPregnancy Complications, HematologicChromosome BandingFetusDermatoglyphicsPregnancy, ProlongedPre-EclampsiaPregnancy, TwinIn Situ Hybridization, FluorescenceChorionic Villi SamplingAbortion, InducedTranslocation, GeneticMonosomyChromosomes, Human, Pair 8Pregnancy, AbdominalUterusFetal Growth RetardationPregnancy Complications, ParasiticNeckFertilization in VitroCongenital AbnormalitiesPregnancy MaintenanceEmbryo ImplantationEmbryo TransferChromosomes, Human, Pair 12Prenatal CareChromosomes, Human, 19-20Amniotic FluidChromosomes, Human, 4-5Chromosomes, Human, Pair 7Abortion, TherapeuticMaternal-Fetal ExchangeAbortion, EugenicParityPrenatal Exposure Delayed EffectsBirth WeightProspective StudiesCesarean SectionPregnancy Reduction, MultifetalIntellectual DisabilityFetal HeartHypertension, Pregnancy-InducedRetrospective StudiesChromosomes, Human, 1-3TwinsProgesteroneAbortion, HabitualChorionic Gonadotropin