Down SyndromeSyndromeChromosomes, Human, Pair 21Prenatal DiagnosisAdolescent DevelopmentTrisomyMaternal AgeMetabolic Syndrome XEstriolPregnancy Trimester, SecondPregnancyLongitudinal StudiesAdolescent BehaviorAge FactorsAmniocentesisInfant, NewbornLeukemia, Megakaryoblastic, AcuteRisk FactorsFetal DiseasesChromosomes, Human, 21-22 and YNephrotic SyndromePersonality DevelopmentAbortion, EugenicIntellectual DisabilitySjogren's SyndromeAdolescent PsychologyTurner SyndromeKaryotypingAbnormalities, MultiplePubertyalpha-FetoproteinsNasal BoneSex FactorsNuchal Translucency MeasurementBrainNondisjunction, GeneticUltrasonography, PrenatalProspective StudiesPregnancy, High-RiskPeer GroupPregnancy Trimester, FirstPhenotypeFollow-Up StudiesChild DevelopmentWilliams SyndromeParentsPrevalenceParent-Child RelationsDisease Models, AnimalCohort StudiesCase-Control StudiesMyelodysplastic SyndromesPregnancy-Associated Plasma Protein-AAgingChorionic Gonadotropin, beta Subunit, HumanJuvenile DelinquencyPolycystic Ovary SyndromeQuestionnairesHeart Defects, CongenitalCushing SyndromeInterpersonal RelationsFalse Positive ReactionsPaternal AgeDiGeorge SyndromeAcute Coronary SyndromeTime FactorsAge of OnsetConduct DisorderChromosome DisordersPregnancy in AdolescenceRetrospective StudiesSocial EnvironmentTourette SyndromeAlcohol DrinkingAnalysis of VarianceHorner SyndromeMotor ActivitySocial BehaviorAntisocial Personality DisorderAggressionCraniofacial AbnormalitiesPrader-Willi SyndromeLong QT SyndromeBiological MarkersParentingStanford-Binet TestMutationGestational AgeCross-Sectional StudiesHeart Septal DefectsBody Mass IndexPedigreeSubstance-Related DisordersGuillain-Barre SyndromeHemolytic-Uremic SyndromeSibling RelationsChild Behavior DisordersAlzheimer DiseaseDuodenal ObstructionGenetic Testing