TrisomyPrenatal DiagnosisDown SyndromePrenatal Exposure Delayed EffectsPrenatal CareUltrasonography, PrenatalPregnancyKaryotypingChromosomes, Human, Pair 18Fetal DiseasesChromosome DisordersChromosomes, Human, 16-18Chromosomes, Human, Pair 21Abnormalities, MultipleChromosomes, Human, Pair 13MosaicismNuchal Translucency MeasurementAmniocentesisPregnancy Trimester, FirstPregnancy Trimester, SecondMaternal AgeChromosome AberrationsChorionic Gonadotropin, beta Subunit, HumanChorionic Villi SamplingChromosomes, Human, 13-15Nondisjunction, GeneticChromosomes, Human, 6-12 and XGestational AgeInfant, NewbornPregnancy-Associated Plasma Protein-AAneuploidyPregnancy, High-RiskNasal BoneChromosomes, Human, 21-22 and YAbortion, EugenicChromosome BandingFetusDermatoglyphicsCrown-Rump LengthIn Situ Hybridization, FluorescenceTranslocation, GeneticChromosomes, Human, Pair 8MonosomyMaternal ExposureChromosomes, Human, Pair 12Chromosomes, Human, 4-5NeckPregnancy OutcomeChromosomes, Human, Pair 7Chromosomes, Human, 19-20Genetic CounselingIntellectual DisabilityFetal HeartChromosomes, Human, 1-3Congenital AbnormalitiesFetal DeathPregnancy ComplicationsSyndromeMaternal Serum Screening TestsHeart Defects, CongenitalPrenatal InjuriesSex Chromosome AberrationsAbortion, TherapeuticPregnancy Trimester, ThirdCytogeneticsPolyhydramniosCytogenetic AnalysisAbortion, SpontaneousTurner SyndromeForeheadPedigree