neural tube defects occur during pregnancy in the 3rd week.
neural tube defects occur during pregnancy in the 3rd week.
when do neural tube defects occur during pregnancy?
the 3rd week
Na
Na
a deficiency of folate itself does not cause neural tube defects. the association seen between reduced neural tube defects and folic acid supplementation is due to a gene-environment interaction such as vulnerability caused by the c677t methylenetetrahydrofolate reductase (mthfr) variant. supplementing folic acid during pregnancy reduces the prevalence of ntds by not exposing this otherwise sub-clinical mutation to aggravating conditions. other potential causes can include folate antimetabolites (such as methotrexate), mycotoxins in contaminated corn meal, arsenic, hyperthermia in early development, and radiation. maternal obesity has also been found to be a risk factor for ntds. studies have shown that both maternal cigarette smoking and maternal exposure to secondhand smoke increased the risk for neural tube defects in offspring. a mechanism by which maternal exposure to cigarette smoke could increase ntd risk in offspring is suggested by several studies that show an association between cigarette smoking and elevations of homocysteine levels. cigarette smoke during pregnancy, including secondhand exposure, can increase the risk of neural tube defects. all of the above may act by interference with some aspect of normal folic acid metabolism and folate linked methylation related cellular processes as there are multiple genes of this type associated with neural tube defects.
neural tube defect