{"id":"927498a7-b8dc-597a-b983-943060d16c44","stable_key":"ec174d5a-4903-5745-8646-df0e9d4265e8:fol-ntd-recurrence-randomized","predicate":"reduced_recurrence_in_trial","statement":"The MRC trial recorded 6 NTD-affected pregnancies in folic-acid groups and 21 in groups without folic acid: relative risk 0.28 (95% CI 0.12–0.71).","claim_class":"observational","status":"source_derived_draft","evidence_grade":"ungraded","direction":"negative","is_public":true,"mechanism_event_id":"258be4f3-fd60-5e36-8c88-4965c3054234","mechanism_event_label":"Adding folic acid before and early in pregnancy prevented many recurrences in this high-risk trial.","subject":{"id":"d322bfef-5135-599f-82e6-0aa58748dc8b","slug":"folic-acid","display_name":"Folic acid","entity_type_key":"small_molecule"},"object":{"id":"763ed160-e614-5def-8cbe-16ecb2e2d003","slug":"neural-tube-defect-incidence","display_name":"Neural-tube defect incidence","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"258be4f3-fd60-5e36-8c88-4965c3054234","stable_key":"ec174d5a-4903-5745-8646-df0e9d4265e8:fol-ntd-recurrence-randomized-event","event_type":"observed_intervention","label":"Adding folic acid before and early in pregnancy prevented many recurrences in this high-risk trial.","description":"The MRC trial recorded 6 NTD-affected pregnancies in folic-acid groups and 21 in groups without folic acid: relative risk 0.28 (95% CI 0.12–0.71).","status":"provisional","compartment":null,"participants":[{"entity":{"id":"d322bfef-5135-599f-82e6-0aa58748dc8b","slug":"folic-acid","display_name":"Folic acid","entity_type_key":"small_molecule"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"763ed160-e614-5def-8cbe-16ecb2e2d003","slug":"neural-tube-defect-incidence","display_name":"Neural-tube defect incidence","entity_type_key":"cellular_process"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""}]},"contexts":[{"dimension":"experimental_model","value_text":"Randomized double-blind factorial trial at 33 centers in seven countries; 1817 women with a previous NTD-affected pregnancy, 1195 informative pregnancies.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"Folic acid 4 mg/day, seven other vitamins, both or neither from randomization to 12 weeks of pregnancy. Historical trial exposure.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Not every NTD was prevented. Early stopping can inflate an effect estimate; the report also supplied an adjusted estimate. The trial did not isolate a cellular mechanism.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Folate and folic acid research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"folate","display_name":"Folate (vitamin B9)","entity_type_key":"chemical_species"}},{"dimension":"organism","value_text":"Homo sapiens","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"Adding folic acid before and early in pregnancy prevented many recurrences in this high-risk trial.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[fol-mrc1991] Prevention of neural tube defects: results of the Medical Research Council Vitamin Study. MRC Vitamin Study Research Group (1991). https://pubmed.ncbi.nlm.nih.gov/1677062/ DOI: 10.1016/0140-6736(91)90133-A","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Pregnancy and fetal developmental outcomes","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"81272f8f-a9c3-5eec-9e72-92889a23be5e","evidence_kind":"source_excerpt","locator":"Lines 1359-1369","start_line":1359,"end_line":1369,"excerpt":"### fol-ntd-recurrence-randomized\nThe MRC trial recorded 6 NTD-affected pregnancies in folic-acid groups and 21 in groups without folic acid: relative risk 0.28 (95% CI 0.12–0.71).\nCondition category: normal\nnutrient_topic: Folate and folic acid research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: Adding folic acid before and early in pregnancy prevented many recurrences in this high-risk trial.\norganism: Homo sapiens\ntissue_or_cell_type: Pregnancy and fetal developmental outcomes\nexperimental_model: Randomized double-blind factorial trial at 33 centers in seven countries; 1817 women with a previous NTD-affected pregnancy, 1195 informative pregnancies.\nlimitations: Not every NTD was prevented. Early stopping can inflate an effect estimate; the report also supplied an adjusted estimate. The trial did not isolate a cellular mechanism.\nexposure: Folic acid 4 mg/day, seven other vitamins, both or neither from randomization to 12 weeks of pregnancy. Historical trial exposure.\n[fol-mrc1991] Prevention of neural tube defects: results of the Medical Research Council Vitamin Study. MRC Vitamin Study Research Group (1991). https://pubmed.ncbi.nlm.nih.gov/1677062/ DOI: 10.1016/0140-6736(91)90133-A","model_system":"Randomized double-blind factorial trial at 33 centers in seven countries; 1817 women with a previous NTD-affected pregnancy, 1195 informative pregnancies.","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [fol-mrc1991] Prevention of neural tube defects: results of the Medical Research Council Vitamin Study. MRC Vitamin Study Research Group (1991). https://pubmed.ncbi.nlm.nih.gov/1677062/ DOI: 10.1016/0140-6736(91)90133-A","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"f4ce1a62-9582-5f7a-84f5-a23d0e1bfc68","stable_key":"import-ec174d5a-4903-5745-8646-df0e9d4265e8","title":"Folate and folic acid: mechanisms, deficiency and nutrient interactions (2026-09-17)","document_type":"imported_text","citation_label":"AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text.","file_path":"","sha256":"e564d43989ece1006c95cd0748e9af6fe369074599a2eebba0a99ebff864b0dd","revision_id":"76674a33-b2a1-5e41-b71b-44399038ff7c","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}