Chorionic VilliChorionic Villi SamplingPrenatal DiagnosisAmniocentesisPregnancy Trimester, FirstPregnancyTrophoblastsPlacentaFetal DiseasesChromosome DisordersFetomaternal TransfusionKaryotypingPregnancy, TubalGestational AgeUltrasonography, PrenatalAbortion, SpontaneousMethemalbuminChorionTrisomyAmniotic FluidPlacentationDown SyndromeCordocentesisPregnancy, High-RiskMaternal AgeMosaicismAmnionAneuploidyHydatidiform MoleNeckAbortion, EugenicChromosome AberrationsDeciduaAbortion, SepticCrown-Rump LengthPregnancy Reduction, MultifetalPregnancy Trimester, SecondFetusNuchal Translucency MeasurementPregnancy, MultipleIntestine, SmallPre-EclampsiaPregnancy Trimester, ThirdJejunumGenetic CounselingIntestinal Mucosabeta-ThalassemiaAbortion, InducedPregnancy OutcomeChoriocarcinomaLeukemia Inhibitory Factor Receptor alpha SubunitMicrovilliHeterozygote DetectionChromosomes, Human, Pair 18IleumFetal DeathAbnormalities, MultipleBasement MembraneImmunohistochemistryFluorescent Antibody Technique