Twins, MonozygoticDiseases in TwinsTwinsTwins, DizygoticTwinning, MonozygoticSuperfetationTwins, ConjoinedTwin Studies as TopicGestational AgeBirth WeightApgar ScorePregnancyInfant, NewbornRespiratory Distress Syndrome, NewbornInfant, Very Low Birth WeightIntensive Care Units, NeonatalTripletsPregnancy, TwinDermatoglyphicsPregnancy, MultipleEnvironmentRetrospective StudiesQuadrupletsQuintupletsFetofetal TransfusionPhenotypePregnancy Reduction, MultifetalGenetic Predisposition to DiseaseGene-Environment InteractionRegistriesInheritance PatternsEmbryo TransferGenetics, BehavioralHeredityMosaicism