Neural Tube DefectsSpinal DysraphismSpina Bifida OccultaSpina Bifida CysticaAnencephalyNeural TubeMeningomyeloceleFolic AcidEncephalocelePregnancyNeurulationVitamin B ComplexFolic Acid DeficiencyPrenatal DiagnosisPreconception CareHydrocephalusCongenital AbnormalitiesFood, FortifiedAbortion, TherapeuticFourth VentricleFolate Receptors, GPI-AnchoredInfant, NewbornHomocysteineVitamin B 12Folate Receptor 1Prenatal CareDietary Supplementsalpha-FetoproteinsMethylenetetrahydrofolate Reductase (NADPH2)Nervous SystemFetal DeathAmniotic FluidMethylenetetrahydrofolate Dehydrogenase (NADP)Reduced Folate Carrier ProteinNeural CrestTetrahydrofolatesAir Pollution, RadioactiveAmniocentesisEmbryo, MammalianGene Expression Regulation, DevelopmentalCerebrospinal Fluid ShuntsFetal DiseasesPaired Box Transcription FactorsMeningoceleIrelandIndividuationMice, Mutant StrainsMouth AbnormalitiesGestational AgeCase-Control StudiesVitamin B 12 DeficiencyFlourCentral Nervous SystemEmbryonic and Fetal DevelopmentChick EmbryoPregnancy Trimester, FirstUltrasonography, PrenatalTailAbnormalities, MultipleZinebPregnancy Complications5,10-Methylenetetrahydrofolate Reductase (FADH2)Abortion, InducedAbnormalities, Drug-InducedVitaminsMaternal ExposureBody PatterningPrevalenceIn Situ HybridizationUrinary Bladder, NeurogenicCaliforniaNotochordMutationAbnormalities, Severe TeratoidRisk FactorsThymidine MonophosphateFormate-Tetrahydrofolate LigasePregnancy in DiabeticsEmbryonic DevelopmentManebAbortion, SpontaneousAcrocallosal SyndromePhenotypeLumbosacral RegionPrenatal Nutritional Physiological PhenomenaMorphogenesisGenotypeTeratogensTranscription FactorsDeanolHomozygoteRiskPollen TubeSpineMethylenetetrahydrofolate Dehydrogenase (NAD+)BreadCrown-Rump LengthTranscobalaminsArnold-Chiari MalformationHeart Defects, Congenital