AmniocentesisTrisomyDown SyndromeChorionic Villi SamplingAmniotic FluidPrenatal DiagnosisPregnancy Trimester, SecondChromosome DisordersPregnancyFetal DiseasesUltrasonography, PrenatalMaternal AgeKaryotypingCordocentesisPregnancy, High-RiskChromosome Aberrationsalpha-FetoproteinsGestational AgePregnancy Trimester, FirstMosaicismChromosomes, Human, Pair 18Rh IsoimmunizationAbnormalities, MultipleEstriolAbortion, EugenicAneuploidyGenetic CounselingTest Anxiety ScaleChromosomes, Human, 16-18ChorioamnionitisSex Chromosome AberrationsCongenital AbnormalitiesChromosomes, Human, Pair 21Abortion, SpontaneousChromosomes, Human, Pair 13Custodial CareFetal DeathLymphangioma, CysticNuchal Translucency MeasurementPregnancy OutcomeAbortion, InducedBiological DressingsFetal Membranes, Premature RuptureInfant, NewbornPregnancy, TwinChorionic Gonadotropin, beta Subunit, HumanTranslocation, GeneticAbortion, TherapeuticObstetric Labor, PrematureNeckChromosomes, Human, 13-15Pregnant WomenNondisjunction, GeneticChromosomes, Human, 6-12 and XFetusNeural Tube DefectsIatrogenic DiseaseErythroblastosis, FetalAmnionFoot Deformities, CongenitalCytogeneticsIn Situ Hybridization, FluorescenceTwinsSex Determination AnalysisPregnancy-Associated Plasma Protein-AKaryotypeFetal Organ MaturityNasal BoneChromosomes, Human, 21-22 and YPolyhydramniosBlood Transfusion, IntrauterineFreedomPregnancy, MultipleFalse Positive ReactionsChromosome BandingChorionic VilliDermatoglyphicsSensitivity and SpecificityCrown-Rump LengthFetofetal Transfusion