Nasal BoneBone and BonesDown SyndromeBone RemodelingNasal MucosaBone DensityCrown-Rump LengthUltrasonography, PrenatalNuchal Translucency MeasurementBone ResorptionPregnancy Trimester, FirstBone MarrowPregnancy Trimester, SecondBone NeoplasmsBone DevelopmentBone Marrow CellsBone DiseasesSkull FracturesNasal PolypsBone RegenerationNasal SeptumGestational AgePregnancyBone MatrixBone Marrow TransplantationBone TransplantationMaternal AgeChorionic Villi SamplingNasal Lavage FluidChromosomes, Human, 16-18Pregnancy-Associated Plasma Protein-AChorionic Gonadotropin, beta Subunit, HumanNose Deformities, AcquiredBone SubstitutesBone Diseases, MetabolicFractures, BoneFacial BonesImaging, Three-DimensionalBone Morphogenetic ProteinsNoseChromosomes, Human, 13-15Nasal DecongestantsBone Morphogenetic Protein 2OsteogenesisTemporal BoneParietal BoneObserver VariationFemurPregnancy, High-RiskFetal DiseasesTrisomy