[Is low or high body weight associated with an increased risk of neural tube defects?].
Periconceptional use of 0.4 mg folic acid reduces the risk of neural tube defects (NTD) considerably, but not by 100%. Body weight may be an additional risk factor. Restricted energy intake periconceptionally was associated with an increased risk in a case-control study. Other surveys observed an elevated NTD risk for mothers not gaining enough weight during pregnancy. Surveys on low body weight before pregnancy revealed contradictory results, probably reflecting the heterogenicity of this group of women. Additional studies are needed to judge the NTD risk associated with restricted energy intake. Obesity before pregnancy doubles the NTD risk, independent of periconceptional use of folic acid supplements or diabetes. There is some evidence that in obese women a higher dose of folic acid is needed to prevent NTD. The present findings in relation to obesity have to be confirmed in cohort and intervention studies. Recommendations regarding the body weight of potentially pregnant women should consider the importance of an adequate nutritional status. In addition, periconceptional use of folic acid supplements should be promoted.
Eichholzer
M
M
Institut für Sozial- und Präventivmedizin der Universität Zürich. monika.eichholzer@balcab.ch
D015992:Body Mass Index; D002149:Energy Intake; D005060:Europe; D005260:Female; D006306:Health Surveys; D006801:Humans; D007231:Infant, Newborn; D009436:Neural Tube Defects / Q000453:epidemiology* / Q000209:etiology; D050177:Overweight; D011247:Pregnancy; D018570:Risk Assessment; D013223:Statistics as Topic; D013851:Thinness; D014481:United States