Neural Tube DefectsNeural TubeAnencephalySpinal DysraphismFolic AcidSpina Bifida OccultaNeurulationSpina Bifida CysticaEncephalocelePregnancyMeningomyeloceleVitamin B ComplexPreconception CarePrenatal DiagnosisFood, FortifiedCongenital AbnormalitiesFolic Acid DeficiencyAbortion, Therapeuticalpha-FetoproteinsNeural CrestInfant, NewbornNervous SystemAir Pollution, RadioactiveAmniocentesisPrenatal CareEmbryo, MammalianAmniotic FluidDietary SupplementsGene Expression Regulation, DevelopmentalMouth AbnormalitiesIrelandCentral Nervous SystemFetal DeathChick EmbryoFlourHomocysteineVitamin B 12TailZinebMice, Mutant StrainsPaired Box Transcription FactorsMethylenetetrahydrofolate Reductase (NADPH2)Embryonic and Fetal DevelopmentVitamin B 12 DeficiencyBody PatterningIn Situ HybridizationMethylenetetrahydrofolate Dehydrogenase (NADP)NotochordVitaminsEmbryonic DevelopmentMutationFetal DiseasesPregnancy in DiabeticsManebPregnancy ComplicationsFormate-Tetrahydrofolate LigaseMorphogenesisGestational AgeThymidine MonophosphateTeratogensDeanolPollen TubeCase-Control StudiesPhenotypeMaternal ExposureFolate Receptor 1Prenatal Nutritional Physiological PhenomenaTranscription FactorsAbnormalities, Drug-InducedAbortion, InducedAbnormalities, MultipleTetrahydrofolatesCleft LipHeart Defects, CongenitalHomeodomain ProteinsMolecular Sequence DataTranscobalaminsBreadCraniofacial AbnormalitiesPregnancy Trimester, SecondHomozygotePregnancy Trimester, FirstThiocholineMeningoceleMice, KnockoutFolate Receptors, GPI-AnchoredGenes, LethalRisk FactorsPrevalenceHydrocephalusQuailMice, Neurologic MutantsEstriolDown SyndromeCleft PalateRiskMaternal Nutritional Physiological PhenomenaCerebral AqueductTrisomyCell Polarity