Nasal BoneBone and BonesDown SyndromeNasal MucosaCrown-Rump LengthUltrasonography, PrenatalNuchal Translucency MeasurementPregnancy Trimester, FirstBone RemodelingPregnancy Trimester, SecondBone DensitySkull FracturesNasal PolypsNasal SeptumGestational AgePregnancySerial PassageBone ResorptionMaternal AgeBone MarrowChorionic Villi SamplingNasal Lavage FluidChromosomes, Human, 16-18Chorionic Gonadotropin, beta Subunit, HumanPregnancy-Associated Plasma Protein-ANose Deformities, AcquiredBone NeoplasmsBone Marrow CellsBone DevelopmentBone DiseasesImaging, Three-DimensionalNoseChromosomes, Human, 13-15Nasal DecongestantsFacial BonesBone RegenerationBone MatrixObserver VariationBone Marrow TransplantationPregnancy, High-RiskBone TransplantationFetal DiseasesTrisomy