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The twentieth century
Published in Michael J. O’Dowd, The History of Medications for Women, 2020
It is now known that the minimum daily non-pregnant requirement of folic acid is 50 ug while pregnant patients require 400 ug per day, the recommended dose for the prevention of ‘first occurrence’ NTD. Supplementation should begin prior to and be continued for the first 12 weeks, of pregnancy. The major neural tube defects are spinal bifida (51%), anencephalus (40%), encephalooele (8%) and iniencephaly (1%) and are due to failure of the embryonal neural tube to close normally. Folic acid supplementation can prevent up to 70% of NTDs but for the remaining 30% of women who seem to be folate-resistant there is no preventative therapy.
Epidemiology of Neural Tube Defects
Published in Michele Kiely, Reproductive and Perinatal Epidemiology, 2019
Neural tube defects include anencephalus (including craniorachischisis), spina bifida (including meningocele, myelocele and usually encephalocele) and iniencephaly. Few data specific to iniencephaly or encephalocele are available. Therefore attention will be focused on anencephalus and spina bifida. More evidence is available on isolated anencephalus than on spina bifida as investigators usually have greater confidence in the completeness of ascertainment of cases with anencephalus.
Cranial and Facial Defects
Published in Asim Kurjak, CRC Handbook of Ultrasound in Obstetrics and Gynecology, 2019
In iniencephaly, a severely deformed fetus shows the extreme retroflexion of the head with fusion of occiput to the cervical vertebrae (Figures 10 and 11). Rachishisis exists in most cases, but defective spinal cord and column are usually covered dorsally by brain cerebellum and skin so that the open neural plate and vertebra are not seen on the surface.
Association of Fetal MTHFR C677T Polymorphism with Susceptibility to Neural Tube Defects: A Systematic Review and Update Meta-Analysis
Published in Fetal and Pediatric Pathology, 2022
Razieh Sadat Tabatabaei, Neda Fatahi-Meibodi, Bahare Meibodi, Atiyeh Javaheri, Hajar Abbasi, Amaneh Hadadan, Reza Bahrami, Seyed Reza Mirjalili, Mojgan Karimi-Zarchi, Hossein Neamatzadeh
As this study is a meta-analysis (secondary analysis) of previously published data, the ethical approval and patient consent were not required. We performed a comprehensive literature search on electronic databases including PubMed, EMBASE, Wed of Science, Elsevier, Cochrane Library, Google Scholar, SciELO, SID, VIP, WanFang, Chinese Biomedical Database (CBD) and Chinese National Knowledge Infrastructure (CNKI) to identify all relevant studies evaluating the association of fetal MTHFR C677T polymorphism with NTDs risk up to April 10, 2020. The combinations of the following Medical Subject Headings (MeSH) and keywords were used to search the eligible studies: (‘‘Neural Tube Defects’’ OR ‘‘NTDs’’ OR ‘‘Neural Tube Closure’’ OR ‘‘Meningomyelocele’’ OR ‘‘Anencephaly’’ OR ‘‘Encephalocele’’ OR ‘‘Hydranencephaly’’ OR ‘‘Iniencephaly’’ OR ‘‘Spina bifida’’ OR ‘‘Spina Bifida Cystica’’ OR ‘‘Spina Bifida Occulta’’ OR ‘‘Spinal Dysraphism’’) AND (“Methylenetetra-Hydrofolate Reductase” OR ‘‘MTFR’’ OR “Methionine Synthase Reductase” OR “Folate Pathway’’) and (‘‘MTHFR C677T’’ OR ‘‘C677T’’ OR ‘‘rs1801133’’ OR ‘‘p.Ala222Val’’ OR ‘‘A222V’’ OR ‘‘g.11796321G > A’’) AND (‘‘Gene’’ OR ‘‘Genotype’’ OR ‘‘Allele’’ OR ‘‘Single Nucleotide Polymorphisms’’ OR ‘‘SNPs’’ OR ‘‘Polymorphism’’ OR ‘‘Substitution’’ OR ‘‘Mutation’’ ‘‘Mutant’’ OR ‘‘Variation’’ OR ‘‘Variant’’). To maximize the number of potential identified studies, the reference lists of all retrieved articles, reviews and meta-analyses were also considered by manual searching. Languages were limited to English, Farsi, Portuguese and Chinese. However, we did have any restrictions on ethnicity, country of origin, sample size, or publication date to avoid any potential publication bias.